Introduction: The medical profession has a very close interaction with the medical devices industry to develop cutting edge medical technology and improve existing products. There is no doubt that innovation and creativity are essential to the development and evolution of therapeutic and medical devices. This often occurs outside the laboratories of the medical device companies. The industry support of research, audits, device registries and user groups where results are reported and enhancements of products and new products developed, is important. Commentary: The Medical Technology Association of Australia (MTAA) Code of Practice facilitates ethical interactions with the profession and with others within the medical technology industry. There is a Code Complaints panel and the Code Monitoring Committee. The Code Complaints panel will hear complaints about company activities against the Code. The Code Monitoring Committee has a proactive role in examining company behaviour against the Code and is not dependent upon a complaint being received. The AMA supports the MTAA’s efforts to strengthen the Code of Practice and its compliance activities. This is industry self-regulation at work. Orthopaedic surgeons have a responsibility to ensure that their participation in collaborative efforts with medical device companies is consistent with their duties towards their patients and towards society at large. Transparency is the key. We must always disclose financial or other arrangements to peers, patients and Ethics Committees. This will improve confidence in the self-governing role of the medical profession. Our relationship with a medical device company should have the primary objective of the advancement of the health of patients. Codes of Conduct for the profession are helpful in guiding expectations and are becoming more prescriptive. Conclusion: The close and essential collaboration between the medical profession and medical device industries will always come under scrutiny. The close working relationship with the MTAA helps to ensure our collaboration with these industries is ethically robust. What matters most is that our patients get the medicines and the devices that are right for them and deliver high quality patient outcomes. We must ensure our position is unambiguous in that process

In 2009, a multidisciplinary team of orthopaedic surgeons, material scientists, and cell biologists created a consortium focused on developing novel biomaterials for cartilage regeneration. After years of hard work across scientific boundaries, the team discovered a solution that could benefit a large number of patients. However, the research team was faced with a question on how to proceed. Whether to continue the scientific path of unravelling the mysteries of cartilage regeneration or to focus on bringing the invention from bench to bedside? The latter would mean commercialisation of the invention, and for the scientists, taking a completely new career path. Taking this turn would mean risking the team members' scientific career, since running a start-up would inevitably mean lesser publications and other scientific merits in the forthcoming years. On the other hand, there was the potential to help a vast amount of patients. The team decided that the invention, a biodegradable weight-adaptive medical device for cartilage regeneration, was too promising to be left aside, so they made the choice to transform from academic researchers to entrepreneurs. Thus, Askel Healthcare Ltd was founded in March 2017. For a start-up operating in medical device sector, the company has a unique feature: the founding team is all-female. Not intentionally, but by a mere “side effect” of gathering the best talents to get the job done. The team continues to foster its strong scientific background, which is a true asset for a company focusing on tackling the big unmet medical need of cartilage regeneration

Introduction

Many worldwide regulatory authorities recommend regular surveillance of metal-on-metal hip arthroplasty patients given high failure rates. However concerns have been raised about whether such regular surveillance, which includes asymptomatic patients, is evidence-based and cost-effective. We determined: (1) the cost of implementing the 2015 MHRA surveillance in “at-risk” Birmingham Hip Resurfacing (BHR) patients, and (2) how many asymptomatic hips with adverse reactions to metal debris (ARMD) would have been missed if patients were not recalled.

The importance of registries has been brought into focus by recent UK national reports focusing on implant (Cumberlege) and surgeon (Paterson) performance. National arthroplasty registries provide real-time, real-world information about implant, hospital, and surgeon performance and allow case identification in the event of product recall or adverse surgical outcomes. They are a valuable resource for research and service improvement given the volume of data recorded and the longitunidal nature of data collection. This review discusses the current value of registry data as it relates to both clinical practice and research.

Cite this article: Bone Joint J 2023;105-B(4):356–360.

Despite the vast quantities of published artificial intelligence (AI) algorithms that target trauma and orthopaedic applications, very few progress to inform clinical practice. One key reason for this is the lack of a clear pathway from development to deployment. In order to assist with this process, we have developed the Clinical Practice Integration of Artificial Intelligence (CPI-AI) framework – a five-stage approach to the clinical practice adoption of AI in the setting of trauma and orthopaedics, based on the IDEAL principles (https://www.ideal-collaboration.net/). Adherence to the framework would provide a robust evidence-based mechanism for developing trust in AI applications, where the underlying algorithms are unlikely to be fully understood by clinical teams.

Cite this article: Bone Joint Res 2024;13(9):507–512.

Abstract

MAGnetic Expansion Control (MAGEC) rods are used in the surgical treatment of children with early onset scoliosis. The magnetically controlled lengthening mechanism enables rod distractions without the need for repeated invasive surgery. The CE certification of these devices was suspended in March 2021 due, primarily, to performance evidence gaps in the documents provided by the manufacturer to regulators and notified bodies. MAGEC rods are therefore not permitted for use in countries requiring CE marking. This was a survey of 18 MAGEC rod surgeons in the UK about their perception of the impact of the CE suspension on the clinical management of their patients. Unsurprisingly, virtually all perceived a negative impact, reflecting the complexity of this patient group. Reassuringly, these surgeons are highly experienced in alternative treatment methods.

Cite this article: Bone Jt Open 2022;3(2):155–157.

Majority of ultra-high molecular weight polyethylene (UHMWPE) medical devices used in total joint arthroplasty are crosslinked using gamma radiation to improve wear resistance. Alternative methods of crosslinking are urgently needed to replace gamma radiation due to rapid decline in its supply. Peroxide crosslinking is a candidate method with widespread industrial applications. Oxidative stability and biocompatibility, which are critical requirements for medical device applications, can be achieved using vitamin-E as an additive and by removing peroxide by-products through high temperature melting, respectively. We investigated compression molded UHMWPE/vitamin-E/di-cumyl peroxide blends followed by high-temperature melting in inert gas as a material candidate for tibial knee inserts. Wear resistance increased and mechanical properties remained largely unchanged. Oxidation induction time was higher than most of the other clinically available formulations. The material passed the local-end point biocompatibility tests per ISO 10993. Compounds found in exhaustive extraction were of no concern with margin-of-safety values well above the accepted level, indicating a desirable toxicological risk profile. Peroxide crosslinked, vitamin-E stabilized, and high temperature melted UHMWPE has recently been cleared for clinical use in tibial knee inserts. With all the salient characteristics needed in a material that can provide superior long-term performance in total joint patients, peroxide crosslinking can replace gamma radiation crosslinking of UHMWPE for use in all total joint replacement implant including acetabular liners

In absence of available quantitative measures, the assessment of fracture healing based on clinical examination and X-rays remains a subjective matter. Lacking reliable information on the state of healing, rehabilitation is hardly individualized and mostly follows non evidence-based protocols building on common guidelines and personal experience. Measurement of fracture stiffness has been demonstrated as a valid outcome measure for the maturity of the repair tissue but so far has not found its way to clinical application outside the research space. However, with the recent technological advancements and trends towards digital health care, this seems about to change with new generations of instrumented implants – often unfortunately termed “smart implants” – being developed as medical devices. The AO Fracture Monitor is a novel, active, implantable sensor system designed to provide an objective measure for the assessment of fracture healing progression (1). It consists of an implantable sensor that is attached to conventional locking plates and continuously measures implant load during physiological weight bearing. Data is recorded and processed in real-time on the implant, from where it is wirelessly transmitted to a cloud application via the patient's smartphone. Thus, the system allows for timely, remote and X-ray free provision of feedback upon the mechanical competence of the repair tissue to support therapeutic decision making and individualized aftercare. The device has been developed according to medical device standards and underwent extensive verification and validation, including an in-vivo study in an ovine tibial osteotomy model, that confirmed the device's capability to depict the course of fracture healing as well as its long-term technical performance. Currently a multi-center clinical investigation is underway to demonstrate clinical safety of the novel implant system. Rendering the progression of bone fracture healing assessable, the AO Fracture Monitor carries potential to enhance today's postoperative care of fracture patients

Aim. The use of medical devices has grown significantly over the last decades, and has become a major part of modern medicine and our daily life. Infection of implanted medical devices (biomaterials), like titanium orthopaedic implants, can have disastrous consequences, including removal of the device. For still not well understood reasons, the presence of a foreign body strongly increases susceptibility to infection. These so-called biomaterial-associated infections (BAI) are mainly caused by Staphylococcus aureus and Staphylococcus epidermidis. Formation of biofilms on the biomaterial surface is generally considered the main reason for these persistent infections, although bacteria may also enter the surrounding tissue and become internalized within host cells. To prevent biofilm formation using a non-antibiotic based strategy, we aimed to develop a novel permanently fixed antimicrobial coating for titanium devices based on stable immobilized quaternary ammonium compounds (QACs). Method. Medical grade titanium implants (10×4×1 mm) were dip-coated in a solution of 10% (w/v) hyperbranched polymer, subsequently in a solution of 30% (w/v) polyethyleneimine and 10 mM sodium iodide, using a dip-coater, followed by a washing step for 10 min in ethanol. The QAC-coating was characterized using water contact angle measurements, scanning electron microscopy, FTIR, AFM and XPS. The antimicrobial activity of the coating was evaluated against S. aureus strain JAR060131 and S. epidermidis strain ATCC 12228 using the JIS Z 2801:2000 surface microbicidal assay. Lastly, we assessed the in vivo antimicrobial activity in a mouse subcutaneous implant infection model with S. aureus administered locally on the QAC-coated implants prior to implantation to mimic contamination during surgery. Results. Detailed material characterization of the titanium samples showed the presence of a homogenous and stable coating layer at the titanium surface. Moreover, the coating successfully killed S. aureus and S. epidermidis in vitro. The QAC-coating strongly reduced S. aureus colonization of the implant surface as well as of the surrounding tissue, with no apparent macroscopic signs of toxicity or inflammation in the peri-implant tissue at 1 and 4 days after implantation. Conclusions. An antimicrobial coating with stable quaternary ammonium compounds on titanium has been developed which holds promise to prevent BAI. Non-antibiotic-based antimicrobial coatings have great significance in guiding the design of novel antimicrobial coatings in the present, post-antibiotic era

Recent publications have drawn attention to the fact that some brands of joint replacement may contain variants which perform significantly worse (or better) than their ‘siblings’. As a result, the National Joint Registry has performed much more detailed analysis on the larger families of knee arthroplasties in order to identify exactly where these differences may be present and may hitherto have remained hidden. The analysis of the Nexgen knee arthroplasty brand identified that some posterior-stabilized combinations have particularly high revision rates for aseptic loosening of the tibia, and consequently a medical device recall has been issued for the Nexgen ‘option’ tibial component which was implicated. More elaborate signal detection is required in order to identify such variation in results in a routine fashion if patients are to be protected from such variation in outcomes between closely related implant types. Cite this article: Bone Joint J 2023;105-B(3):221–226

For decades, universities and research centers have been applying modeling and simulation (M&S) to problems involving health and medicine, coining the expression in silico clinical trials. However, its use is still limited to a restricted pool of specialists. It is here proposed an easy-to-use cloud-based platform that aims to create a collaborative marketplace for M&S in orthopedics, where developers and model creators are able to capitalize on their work while protecting their intellectual property (IP), and researcher, surgeons and medical device companies can use M&S to accelerate time and to reduce costs of their research and development (R&D) processes. Digital libraries on . InSilicoTrials.com. are built on collaborations among first-rate research center, model developers, software, and cloud providers (partners). Their access is provided to life science and healthcare companies, clinical centers, and research institutes (users), offering them with several solutions for the different steps of the orthopedics and medical devices R&D process. The platform is built using the Microsoft Azure cloud services, conforming to global standards of security and privacy for healthcare, ensuring that clinical data is properly managed, protected, and kept private. The environment protects the IP of partners against the downloading, copying, and changing of their M&S solutions; while providing a safe environment for users to seamlessly upload their own data, set up and run simulations, analyze results, and produce reports in conformity with regulatory requirements. The proposed platform allows exploitation of M&S through a Software-as-a-Service delivery model. The pay-per-use pricing: 1. provide partners with a strong incentive to commercialize their high-quality M&S solutions; 2. enable users with limited budget, such as small companies, research centers and hospitals, to use advanced M&S solutions. Pricing of the M&S tools is based on specific aspects, such as particular features and computational power required, in agreement with the developing partner, and is distinct for different types of customers (i.e., academia or industry). The first medical devices application hosted on . InSilicoTrials.com. is NuMRis (Numerical Magnetic Resonance Implant Safety), implemented in collaboration with the U.S. F.D.A. Center for Devices and Radiological Health, and ANSYS, Inc. The automatic tool allows the investigation of radiofrequency (RF)-induced heating of passive medical implants, such as orthopedic devices (e.g., rods and screws), pain management devices (e.g., leads), and cardiovascular devices (e.g., stents), following the ASTM F2182-19e2 Standard Test Method. NuMRis promotes the broader adoption of digital evidence in preclinical trials for RF safety analysis, supporting the device submission process and pre-market regulatory evaluation. InSilicoTrials.com. aims at defining a new collaborative framework in healthcare, engaging research centers to safely commercialize their IP, i.e., model templates, simulation tools and virtual patients, by helping clinicians and healthcare companies to significantly expedite the pre-clinical and clinical development phases, and to move across the regulatory approval and HTA processes

AM specifically allows for cost-efficient production of patient-specific Orthopaedic medical devices with unusual designs and properties. A porous design allows to adjust the stiffness of metallic implants to that of the host bone. Beyond traditional metals, like titanium alloys, this talk will review the present state-of-the-art of directly printed absorbable metal families. Physicochemical, mechanical and biological properties of standardized design prototypes from all currently available metal families will be compared and their clinical application potential discussed. The impact of in vitro test environments on comparative corrosion behavior, post manufacturing aspects, and the recent status quo in biocompatibility testing and present knowledge gaps will be addressed

Infections are among the most diffused complications of the implantation of medical devices. In orthopedics, they pose severe societal and economic burden and interfere with the capability of the implants to integrate in the host bone, significantly increasing failure risk. Infection is particularly severe in the case of comorbidities and especially bone tumors, since oncologic patients are fragile, have higher infection rate and impaired osteoregenerative capabilities. For this reason, prevention of infection is to be preferred over treatment. This is even more important in the case of spine surgery, since spine is among the main site for tumor metastases and because incidence of post operative surgical-site infections is significant (up to 15-20%) and surgical options are limited by the need of avoiding damaging the spinal cord. Functionalization of the implant surfaces, so as to address infection and, possibly, co- adjuvate anti-tumor treatments, appears as a breakthrough innovation. Unmet clinical needs in infection and tumors is presented, with a specific focus on the spine, then, new perspectives are highlighted for their treatment

Implant manufacturers develop new products to improve existing fracture fixation methods or to approach new fracture challenges. New implants are commonly tested and approved with respect to their corresponding predecessor products, because the knowledge about the internal forces and moments acting on implants in the human body is unclear. The aim of this study was to evaluate and validate implant internal forces and moments of a complex physiological loading case and translate this to a standard medical device approval test. A finite elements model for a transverse femur shaft fracture (AO/OTA type 32-B2) treated with a locked plate system (AxSOS 3 Ti Waisted Compression Plate Broad, Stryker, Kalamazoo, USA) was developed and experimentally validated. The fractured construct was physiologically loaded by resulting forces on the hip joint from previously measured in-vivo loading experiments (Bergmann et. al). The forces were reduced to a level where the material response in the construct remained linear elastic. Resulting forces, moments and stresses in the implant of the fractured model were analysed and compared to the manufacturers’ approval data. The FE-model accurately predicted the behaviour of the whole construct and the micro motion of the working length of the osteosynthesis. The resulting moment reaction in the working length was 24 Nm at a load of 400 N on the hip. The maximum principle strains on the locking plate were predicted well and did not exceed 1 %. In this study we presented a protocol by the example of locked plated femur shaft fracture to calculate and validate implant internal loading using finite element analysis of a complex loading. This might be a first step to move the basis of development of new implants from experience from previous products to calculation of mechanical behaviour of the implants and therefore, promote further optimization of the implants’ design

Infection of implanted medical devices (biomaterials), like titanium orthopaedic implants, can have disastrous consequences, including removal of the device. These so-called biomaterial-associated infections (BAI) are mainly caused by Staphylococcus aureus and Staphylococcus epidermidis. To prevent biofilm formation using a non-antibiotic based strategy, we aimed to develop a novel permanently fixed antimicrobial coating for titanium devices based on stable immobilized quaternary ammonium compounds (QACs). Medical grade titanium implants were dip-coated in subsequent solutions of hyperbranched polymer, polyethyleneimine and 10 mM sodium iodide, and ethanol. The QAC-coating was characterized using water contact angle measurements, scanning electron microscopy, FTIR, AFM and XPS. The antimicrobial activity of the coating was evaluated against S. aureus strain JAR060131 and S. epidermidis strain ATCC 12228 using the JIS Z 2801:2000 surface microbicidal assay. Lastly, we assessed the in vivo antimicrobial activity in a mouse subcutaneous implant infection model with S. aureus administered locally on the QAC-coated implants prior to implantation to mimic contamination during surgery. Detailed material characterization of the titanium samples showed the presence of a homogenous and stable coating layer at the titanium surface. Moreover, the coating successfully killed S. aureus and S. epidermidis in vitro. The QAC-coating strongly reduced S. aureus colonization of the implant surface as well as of the surrounding tissue, with no apparent macroscopic signs of toxicity or inflammation in the peri-implant tissue at 1 and 4 days after implantation. An antimicrobial coating with stable quaternary ammonium compounds on titanium has been developed which holds promise to prevent BAI. Non-antibiotic-based antimicrobial coatings have great significance in guiding the design of novel antimicrobial coatings in the present, post-antibiotic era. Acknowledgements: This research was financially supported by the Health∼Holland/LSH-TKI call 2021–2022, project 25687, NACQAC: ‘Novel antimicrobial coatings with stable non-antibiotic Quaternary Ammonium Compounds and photosensitizer technology'

The objectives of this study are to evaluate the impact of the CoVID-19 pandemic on the development of relevant emerging digital healthcare trends and to explore which digital healthcare trend does the health industry need most to support HCPs. A web survey using 39 questions facilitating Five-Point Likert scales was performed from 1.8.2020 – 31.10.2020. Of 260 participants invited, 90 participants answered the questionnaire. The participants were located in the Hospital/HCP sector in 11.9%, in other healthcare sectors in 22.2%, in the pharmaceutical sector in 11.1%, in the medical device and equipment industry in 43.3%. The Five-Point Likert scales were in all cases fashioned as from 1 (strongly disagree) to 5 (strongly agree). As the top 3 most impacted digital health care trends strongly impacted by CoVID-19, respondents named:. - remote management of patients by telemedicine, mean answer 4.44. - shared data governance under patient control, mean answer 3.80. - new virtual interaction between HCP´s and medical industry, mean answer 3.76. Respondents were asked which level of readiness of the healthcare system currently possess to cope with the current trend impacted by CoVID-19. - Digital and efficient healthcare logistics, mean answer 1.54. - Integrated health care, mean answer 1.73. - Use of big data and artificial intelligence, mean answer 2.03. Asked if collaborative research in the form of digital data platforms for research data sharing and increasing collaboration with multi-centric consortia would have a positive impact on the healthcare sector, the agreement was high with a value of mean 4.10 on the scale. We can conclude that the impact of COVID-19 appears to be a high agreement of necessary advances in digitalization in the health care sector and in the collaboration of HCPs with the health care industry. Health care professional are unsure, in how far the national health care sector is capable of transformation in healthcare logistics and integrated health care

Abstract. Purpose. Clinical registries are an important aspect of orthopaedic research in assessing the outcomes of surgical intervention and track medical devices. This study aimed to explore the research methodology available to account for patients lost to follow-up (LTFU) specifically in studies related to arthroscopic intervention and whether the rates of patient LTFU are within the acceptable margins for survey studies. Methods. A scoping review, where a literature search for studies from nine arthroscopy registries, was performed on EMBASE, MEDLINE, and the annual reports of each registry. Inclusion criteria included studies with information on patient-reported outcome measures and being based on nine national registries identified. Exclusion criteria included review articles, conference abstracts, studies not based on registry data, and studies from regional, claims-based, or multi-centre registries. Studies were then divided into categories based on method of LTFU analysis used. Results. Thirty-six articles were identified for the final analysis. Categories for LTFU analysis included dropout analyses (n=10), referencing validation studies (n=12), contacting non-responders (n=4), and sensitivity analyses (n=1). Referencing validation studies was the most common method (n=12). Majority (n=35) of the studies exceeded the recommended maximum rates for LTFU. Conclusions. Most arthroscopy studies have rates of LTFU higher than traditionally acceptable. Therefore, any conclusions drawn from these research papers may not be sufficiently valid or free from non-response bias

The Electrospinning Company designs, develops and manufactures biomaterials for use in regenerative medical devices. Since 2012, Ann has led the growth of the company from start-up to supplier of innovative, clinical-grade product to an FDA-approved medical device, evolving the business model and adding capabilities in innovation, manufacturing, quality and alliance management. Ann will share some of the highs and lows of the journey from her perspective as a female leader of a diverse team

Electrospinning of (bio)polymers is a well acknowledged technology used by scientists all over the world to manufacture scaffolds for tissue engineering & 3D cell culture purposes. The ability to control key parameters such as fibre diameter and fibre orientation allow the generation of highly specific scaffolds that closely mimic the native extracellular matrix. Despite the popularity in the R&D lab, the technology itself has only recently seen acceptance as a method for manufacturing clinical-grade medical devices. Subsequently, never before have more electrospun materials obtained market approval (FDA/CE) and are in clinical trials. In this presentation, we share our experience as a manufacturer of clinical-grade medical devices via electrospinning and give insight into the possible applications in orthopaedics

Abstract. Objectives. Additive manufacturing has led to numerous innovations in orthopaedic surgery: surgical guides; surface coatings/textures; and custom implants. Most contemporary implants are made from titanium alloy (Ti-6Al-4V). Despite being widely available industrially and clinically, there is little published information on the performance of this 3D printed material for orthopaedic devices with respect to regulatory approval. The aim of this study was to document the mechanical, chemical and biological properties of selective laser sintering (SLS) manufactured specimens following medical device (TOKA®, 3D Metal Printing LTD, UK) submission and review by the UK Medicines and Healthcare Products Regulatory Agency (MHRA). Methods. All specimens were additively manufactured in Ti-6Al-4V ELI (Renishaw plc, UK). Mechanical tests were performed according to ISO6892-1, ISO9585 and ISO12107 for tensile (n=10), bending (n=3) and fatigue (n=16) respectively (University of Bath, UK). Appropriate chemical characterisation and biological tests were selected according to recommendations in ISO10993 and conducted by external laboratories (Wickham Labs, UK; Lucideon, UK; Edwards Analytical, UK) in adherence with Good Lab Practise guidelines. A toxicological review was conducted on the findings (Bibra, UK). Results. The mechanical tests demonstrated that the material performed to the specification for conventionally manufactured titanium alloy of this type (ISO5832-3). The toxicology review concluded that there were no significant concerns for the health of the patients identified in this evaluation and implantation of the TOKA® device would not result in a significant health risk to patients. Conclusions. Reflecting on our MHRA experience, additive manufacture of orthopaedic devices is still considered to be a ‘novel’ process by regulatory bodies, requiring additional safety evidence. Despite this, our findings demonstrate that there is no difference, mechanically or chemically, to the traditionally manufactured alloy material. We hope to support the widening use of 3D printed titanium alloy orthopaedic devices by publishing our route to regulatory approval. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

After the first big hype on additive manufacturing in medical industry the technology of 3D printing is now reaching a productive stage for some selected applications. These applications range from surgical models for visualisation to patient-specific cutting guides and 3D printed orthopaedic implants. This presentation will guide through current 3D printing applications in medical devices. We will show success stories for products in some of these fields and try to point out to a potential future of fully personalized orthopaedics in polymer and metals. A regulatory view on all aspects of 3D printing will be presented and potential hurdles to expand the full potential of medical device 3D printing

The need for a more durable, metal free, non-osteolytic particle generating material in Total Hip Replacement (THR) is urgently required to reduce revision surgeries. Current used materials; ceramic, metal and UHMWPE remain discrepant for long-term use. Polyimide (MP-1™) is a high performance biopolymer, originating from aerospace industry. MP-1™ is heat resistant, highly cross-linked and exhibits a self-lubrication property required for bearings and articulating joints. Being resistant to fatigue, creep and chemicals and serializable by autoclave or irradiation, MP-1™ is ideal for medical devices. Finalizing pre-clinical testing, two patients were implanted 13 years ago after informed consent. A PM (Post Mortem) retrieval at 6.5 years, showed no measureable wear, a bland synovium, and no osteoclastic or bone marrow reaction. The 13Y patients' hip, a revision from Polyethylene wear to MP-1™, has an unchanged radiograph and is fully active (Fig. 1). The Ethical Committee approved 100 patients with a single surgeon (PJB) post-marketing trial running Delta ceramic femoral ball against MP-1™ liner. Age range is from 81 to 33 years. The younger patients now being offered MP-1™, in view of the retrieval data. The MP-1™ acetabular liner is 4mm thick, as currently used in a LIMA PF shell, which replaces polyethylene, ceramic or dual mobility options. Out of the 78 enrolled patients, 52 patients have the implant for more than 5 years. The only “Complications” in a few patients was an initial squeak which spontaneously disappears by 10 days and never returns. This is likely due to reduced clearance between head and liner and likely easily correctable. There have been no dislocations or restrictions on activity level. Oxford and Harris Hip scores along with radiology, blood and clinical examination are collected during follow-up. MP-1™ liner on Delta ceramic head in THA, or in the future with MP-1 head, looks very promising with advantages of ease of sterilization, insignificant wear, no tissue reactivity and ability to have thin section and larger femoral heads if desired for larger range of motion. MP-1™ biomaterial is used for other medical devices as well such as dental implants and trauma nails, plates and screws. For any figures or tables, please contact the authors directly

This paper describes how advances in three-dimensional printing may benefit the military trauma patient, both deployed on operations and in the firm base. Use of rapid prototype manufacturing to produce a 3D representation of complex fractures that can be held and rotated will aid surgical planning within multidisciplinary teams. Patient-clinician interaction can also be aided using these graspable models. The education of military surgeons could improve with the subsequent accurate, inexpensive models for anatomy and surgical technique instruction. The developing sphere of additive manufacturing (3D printing functional end-use components) lends itself to further advantages for the military orthopaedic surgeon. Military trauma patients could benefit from advances in direct metal laser sintering which enable the manufacture of complex surfaces and porous structures on bio-metallic implants not possible using conventional manufacturing. “Bio-printing” of tissues mimicking anatomical structures has potential for military trauma patients with bone defects. Deployed surgeons operating on less familiar fracture sites could benefit from three-dimensionally printing patient-specific medical devices. These can make operating technically easier, reducing radiation exposure and operating time. Further ahead, it may be possible to contemporaneously 3D print medical devices unavailable from the logistics chain whilst operating in the deployed environment

Nowadays, foot switches are used in almost every operating theatre to support the interaction with medical devices. Foot switches are especially used to release risk-sensitive functions of e.g. the drilling device, the high-frequency device or the X-ray C-arm. In general, the use of foot switches facilitates the work, since they enable the surgeon to use both hands exclusively for the manipulation within the operation procedures. Due to the increasing number of (complex) devices controlled by foot switches, the surgeons face a variety of challenges regarding usability and safety of these human-machine-interfaces. In the future, the approach of integrated medical devices in the OR on the basis of the open communication standard IEEE 11073 gives the opportunity to provide a central surgical cockpit with a universal foot switch for the surgeon, enabling the interaction with various devices different manufacturers. In the framework of the ongoing OR.NET initiative founded on the basis of the OR.NET research project (2012–2016) a novel concept for a universal foot switch (within the framework of a surgical workstation) has been developed in order to optimise the intraoperative workflow for the OR-personnel. Here, we developed three wireless functional models of a universal foot switch together with a standardised modular interface for visual feedback via a central surgical cockpit display. Within the development of our latest foot switch, the requirements have been inter alia to provide adequate functionalities to cover the needs for the interventions in the medical disciplines orthopaedic surgery, neurosurgery and ENT. The evaluation has been conducted within an interaction-centered usability analysis with surgeons from orthopaedics, neurosurgery and ENT. By using the Thinking Aloud technique in a Wizard-of-Oz experiment the usability criteria effectiveness, learnability and user satisfaction have been analysed. Regarding learnability 83.25% of the subjects stated that the usage of the universal foot switch is easy to learn. An average of 77,2% of users rated the usability of the universal foot switch between good and excellent on the SUS scale. The intuitiveness of the graphical user interface has been approved with 91.75% and the controllability with 83.25%. Finally, 86% of the subjects stated a high user satisfaction

Thumb carpometacarpal (CMC) arthritis is a common and disabling condition that can be treated with an operative procedure. Before operative measures, patients typically undergo conservative treatment utilizing methods such as physical therapy and injections. This study aims to determine what clinical modalities are being used for preoperative evaluation and nonoperative therapy and the associated cost prior to operative intervention. We queried Truven Market Scan, a large insurance provider database to identify patients undergoing CMC arthroplasty from 2010 to 2017. Patients were identified by common Current Procedural Terminology (CPT) codes for CMC arthroplasty. All associated CPT codes listed for each patient during the 1 year period prior to operative intervention were collected and filtered to only include those codes associated with the ICD-9/10 diagnosis codes relating to CMC arthritis. The codes were then categorized as office visits, x-ray, injections, physical therapy, medical devices, and preoperative labs. The frequency and associated cost for each category was determined. There were 44,676 patients who underwent CMC arthroplasty during the study period. A total of $26,319,848.36 was charged during the preoperative period, for an average of $589.13 per patient. The highest contributing category to overall cost was office visits (42.1%), followed by injections (13.5%), and then physical therapy (11.1%). The most common diagnostic modality was x-ray, which was performed in 74.7% of patients and made up 11.0% of total charges. Only 49% of patients received at least one injection during the preoperative period and the average number of injections per patient was 1.72. Patients who were employed full time were more likely to receive two or more injections prior to surgery compared to patients who had retired (47% of full-time workers; 34% of retirees). The modalities used for the preoperative evaluation and conservative treatment of CMC arthritis and the associated cost are important to understand in order to determine the most successful and cost-effective treatment plan for patients. Surprisingly, despite the established evidence supporting clinical benefits, many patients do not undergo corticosteroid injections. With office visits being the largest contributor to overall costs, further inquiry into the necessity of multiple visits and efforts to combine visits, can help to reduce cost. Also, with the advent of telemedicine it may be possible to reduce visit cost by utilizing virtual medicine. Determining the best use of telemedicine and its effectiveness are areas for future investigation

Bioabsorbable metals hold a lot of potential as orthopaedic implant materials. Three metal families are currently being investigated: iron (Fe), magnesium (Mg) and zinc (Zn). Currently, however, biodegradation of such implants is poorly predictable. We thus used Direct Metal Printing to additively manufacture porous implants of a standardized bone-mimetic design and evaluated their mechanical properties and degradation behaviour, respectively, under in vivo-like conditions. Atomized powder was manufactured to porous implants of repetitive diamond unit cells, using a ProX DMP 320 (Layerwise, Belgium) or a custom-modified ReaLizer SLM50 metal printer. Degradation behaviour was characterized under static and dynamic conditions in a custom-built bioreactor system (37ºC, 5% CO. 2. and 20% O. 2. ) for up of 28 days. Implants were characterized by micro-CT before and after in vivo-like degradation. Mechanical characterization (according to ISO 13314: 2011) was performed on an Instron machine (10kN load cell) at different immersion times in simulated body fluid (r-SBF). Morphology and composition of degradation products were analysed (SEM, JSM-IT100, JEOL). Topographically identical titanium (Ti-6Al-4V, Ti64) specimen served as reference. Micro-CT analyses confirmed average strut sizes (420 ± 4 μm), and porosity (64%), to be close to design values. After 28 days of in vivo-like degradation, scaffolds were macroscopically covered by degradation products in an alloy-specific manner. Weight loss after cleaning also varied alloy-specifically, as did the change in pH value of the r-SBF. Corrosion time-dependent changes in Young's moduli from 1200 to 800 MPa for Mg, 1000 to 700 MPa for Zn and 48-8 MPa for iron were statistically significant. In summary, DMP allows to accurately control interconnectivity and topology of implants from all three families and micro-structured design holds potential to optimize their degradation speed. This first systematic report sheds light into how design influences degradation behaviour under in vivo-like conditions to help developing new standards for future medical device evaluation

Regulatory bodies impose stringent pre-market controls to certify the safety and compatibility of medical devices. However, internationally recognized standard tests may be expensive, time consuming and challenging for orthopedic implants because of many possible sizes and configurations. In addition, cost and time of standard testing may endanger the feasibility of custom-device production obtained through innovative manufacturing technologies like 3d printing. Modeling and simulation (M&S) tools could be used by manufactures and at point-of-care to improve design confidence and reliability, accelerate design cycles and processes, and optimize the amount of physical testing to be conducted. We propose an integrated cloud platform to perform in silico testing for orthopedic devices, assessing mechanical safety and electromagnetic compatibility, in line with recognized standards and regulatory guidelines. The . InSilicoTrials.com. platform contains two M&S tools for orthopedic devices: CONSELF and NuMRis. CONSELF (. conself.com. ) uses Salome-Meca 2017 to compute static implant stresses and strains on metallic orthopedic devices, following the requirements and considerations of ASTM F2996-20 for non-modular hip femoral stems and ASTM F3161-16 for total knee femoral components. Simulation results were consistent with those reported in the two standards. NuMRis (. numris.insilicomri.com. ) uses ANSYS HFSS and ANSYS Mechanical 2019R3 to compute radio-frequency energy absorption and induced heating in 1.5T and 3T MRI coils, replicating the ASTM F2182-19e2 Standard Test Method. Simulation results were validated against in vitro measurements. The integrated M&S workflow on the cloud platform allows the user to upload the 3D geometry and the material properties of the orthopedic device to be tested, automatically set up the standard testing scenarios, run simulations and process outcome, with the option to summarize the results in accordance with current FDA guidance on M&S reporting. The easy-to-use interfaces of InSilicoTrials tools run through commercial web browsers, requiring no specific expertise in computational methods or additional on-premise software and hardware resources, since all simulations are run remotely on cloud infrastructure. The integrated cloud platform can be used to evaluate design alternatives, test multi-configuration devices, perform multi-objective design optimization and identify worst-case scenarios within a family of implant sizes, or to assess the safety and compatibility of custom-made orthopedic devices. InSilicoTrials.com. is the first cloud platform offering a collection of M&S tools to perform in silico standard testing for orthopedic devices. The proposed tools allow to assess mechanical safety and electromagnetic compatibility before prototyping, preventing risks and criticalities for the patient, and helping manufacturers and point-of-care to accelerate time and reduce costs during the device development. The proposed platform promotes the broader adoption of digital evidence in preclinical trials, supporting the device submission process and pre-market regulatory evaluation, and helping secure regulatory approval

In light of recent regulatory initiatives, medical devices now require additional clinical evidence to prove their safety and efficacy. At the same time, patients' own assessment of their devices' function and performance has gained in importance. The collection of these data allows for a more comprehensive picture of clinical outcomes and complications following total knee arthroplasty (TKA). These trends have led researchers to search for new methods of acquiring, interpreting and disseminating patient-reported outcome measurements (PROMs). The current study assesses the feasibility of a digital platform for collecting PROMs that was recently adapted for TKA patients. It sought to determine patient engagement, survey completion rates, and satisfaction with this platform. Eighty-two patients (mean age, 63.7 years, 59% females) scheduled for TKA were enrolled from one US and six UK sites between January 12, 2018 and April 30, 2018. Patients were supplied with a mobile application (app) that collects a variety of PROMs, including four domains based on the Patient-Reported Outcome Information System (PROMIS™): physical function, depression, pain interference and pain behavior. The platform electronically administers questionnaires using computer-adaptive tests (CATs), which reduce the burden on patients by tailoring follow-up questions to account for their previous answers. Satisfaction with the app was assessed in subset of patients who evaluated its ease-of-use (n=45), likelihood that they would recommend it to family/friends (n=35), and whether they successfully used the information it provided during their recovery (n=31). These scores were taken on a 1 to 10 (worst to best) scale. Patients demonstrated regular engagement with the platform, with 73% using the app at least once a week. Weekly engagement remained high throughout the seven-week post-operative period (Figure 1). There was a 69% completion rate of all PROMIS™ CAT surveys during the study. The four PROMIS™ CAT domains had similar survey completion rates (Figure 2). The subset of patients queried regarding their satisfaction with the app gave it favorable mean scores for ease-of-use (8.8), likelihood to recommend to a family member or friend (8.1), and their success at using its information to improve their recovery (7.4). Initial results support this digital platform's potential for successfully and efficiently collecting large volumes of PROMs. Patients reported high levels of engagement and satisfaction. For any figures or tables, please contact authors directly

Tungsten has been increasing in demand for use in manufacturing and recently, medical devices, as it imparts flexibility, strength, and conductance of metal alloys. Given the surge in tungsten use, our population may be subjected to elevated exposures. For instance, embolism coils made of tungsten have been shown to degrade in some patients. In a cohort of breast cancer patients who received tungsten-based shielding for intraoperative radiotherapy, urinary tungsten levels remained over tenfold higher 20 months post-surgery. In vivo models have demonstrated that tungsten exposure increases tumor metastasis and enhances the adipogenesis of bone marrow-derived mesenchymal stem cells while inhibiting osteogenesis. We recently determined that when mice are exposed to tungsten [15 ppm] in their drinking water, it bioaccumulates in the intervertebral disc tissue and vertebrae. This study was performed to determine the toxicity of tungsten on intervertebral disc. Bovine nucleus pulposus (bNP) and annulus fibrosus (bAF) cells were isolated from bovine caudal tails. Cells were expanded in flasks then prepared for 3D culturing in alginate beads at a density of 1×10. ∧. 6 cells/mL. Beads were cultured in medium supplemented with increasing tungsten concentrations in the form of sodium tungstate [0, 0.5, 5, 15 ug/mL] for 12 days. A modified GAG assay was performed on the beads to determine proteoglycan content and Western blotting for type II collagen (Col II) synthesis. Cell viability was determined by counting live and dead cells in the beads following incubation with the Live/Dead Viability Assay kit (Thermo Fisher Scientific). Cell numbers in beads at the end of the incubation period was determined using Quant-iT dsDNA Assay Kit (Thermo Fisher Scientific). Tungsten dose-dependently decreased the synthesis of proteoglycan in IVD cells, however, the effect was significant at the highest dose of 15 ug/mL. (n=3). Furthermore, although tungsten decreased the synthesis of Col II in IVD cells, it significantly increased the synthesis of Col I. Upregulation of catabolic enzymes ADAMTS4 and −5 were also observed in IVD cells treated with tungsten (n=3). Upon histological examination of spines from mice treated with tungsten [15 ug/mL] in their drinking water for 30 days, disc heights were diminished and Col I upregulation was observed (n=4). Cell viability was not markedly affected by tungsten in both bNP and bAF cells, but proliferation of bNP cells decreased at higher concentration. Surprisingly, histological examination of IVDs and gene expression analysis demonstrated upregulation of NGF expression in both NP and AF cells. In addition, endplate capillaries showed increases in CGRP and PGP9.5 expression as determined on histological sections of mouse IVDs, suggesting the development of sensory neuron invasion of the disc. We provide evidence that prolonged tungsten exposure can induce disc fibrosis and increase the expression of markers associated with pain. Tungsten toxicity may play a role in disc degeneration disease

Introduction. Injectable hydrogels via minimally invasive surgery offer benefits to the healthcare system, reduced risk of infection, scar formation and the cost of treatment. Development of new treatments with the use of novel biomaterials requires significant pre-clinical testing and must comply with regulations before they can reach the bedside. In the European economic area (EEA) one of the first hurdles of this process is attaining the CE marking which protects the health, safety and environmental aspects of a product. Implanted materials fall under the class III medical device EU745 regulation standards. To attain the CE marking for a product parties must provide evidence of the materials safety with an investigational medicinal product dossier (IMPD). Methods and Results. We have been working to develop a new thermoresponsive injectable biomaterial hydrogel (NPgel) for the treatment of intervertebral disc (IVD) disease. A large part of the IMPD requires information on how the hydrogel physical properties change over time in bodily conditions. We have been studying 6 batches of NPgel over 18 months, tracking the materials wet/ dry weight, structure and composition. To date we have found that NPgel in liquids more similar to the body (with protein and salts) appear to be stable and safe, whilst those in distilled water swell and disintegrate over time. Subtle long-term changes to the material composition were found and we are currently investigating its ramifications. Conclusion. The study highlights the need to test materials in detail in physiologically representative environments before approaching the bedside and demonstrates promise for NPgel as a suitable CE candidate. Conflicts of interest: CS and CLM are named inventors on the patent for NPgel/BGel. Funded by the Medical Research Council and Versus Arthritis UK: SNiPER

The ATTUNE™ Knee System (DePuy Synthes) comprises of a tibial insert that is made from AOX™, an antioxidant-stabilized polyethylene. The antioxidant used in AOX is pentaerythritol tetrakis [3-(3, 5-di-tertiary butyl-4-hydroxyphenyl)] propionate (PBHP). A biological risk assessment of the degradation products arising from PBHP has been performed. This assessment focuses on the requirements of ISO 10993–1:2009, ISO 14971:2007, and the Medical Device Directive 93/42/EEC. Because the orthopedic implant is a permanent implant, consideration has been given to all relevant endpoints defined by ISO 10993–1 Biological evaluation of medical devices – Part 1: Evaluation and testing within a risk management process. Comprehensive biocompatibility testing including long-term (26 weeks) subcutaneous implantation has been conducted which confirms the biosafety of the polyethylene compound[1]. In addition to the biological safety testing completed, the overall safety and the associated toxicological risk of exposure to degradation products of PBHP has been given due consideration. The guidelines for the Threshold for Toxicological Concern (TTC) provided by The Product Quality Research Institute (PQRI) Leachables and Extractables Working Group were used in the assessment[2]. This working group is a collaboration of chemists and toxicologists from the U.S. Food and Drug Administration (FDA), industry, and academia. The TTC principle allows safety assessment in the absence of substance-specific hazard data, based on very low levels of exposure to that substance. A Margin of Safety (MOS) is calculated as the ratio of the threshold safety value to the actual exposure quantities determined and used in the assessment. A MOS value greater than 1 is typically judged by risk assessors and regulatory bodies to be unlikely to cause harm and the risk may be considered low. The identity of the degradation products as well as the corresponding 30-day leachable quantities from a water:acetone extraction media has been previously reported [3] and provided here (Table 1). The amount of leachables determined from Table 1 for all products were well below the TTC of 150 ng/device and hence no toxicological risks were identified for these compounds. In order to further examine the toxicological risk assessment, aggressive extraction using Dynamic Head Space (DHS) extraction was done and analytical testing was performed on the degradation products of PBHP using gas chromatography/mass spectrometry (GC /MS). These estimated quantities along with literature information from biological safety studies of the chemicals that were identified from the quantitative GC/MS analysis of degradation products of PBHP were used in the review and toxicological assessment per the methodology described in ISO 14971 and ISO 10993–18. The extraction and analysis confirmed the same sixteen compounds previously identified. The quantities and the calculated margins of safety are summarized (Table 2). In conclusion, upon review of actual test results of PBHP degradation products (Table 1), there is little probability that these organic degradation products would cause a systemic reaction and not be safe. Thus, the potential biological hazards identified in ISO 10993–1:2009 due to the quantified leachables have been verified to be minimal with a high Margin of Safety relative to the Threshold of Toxicological Concern

Biomimicry is defined as the design and production of materials, structures, and systems that are modelled on biological entities and processes. Within the medical device sector, biomimicry uses an ecological standard to judge the “rightness” of biomaterial components and devices. After 3.8 billion years of evolution, nature has learned what works, what is appropriate, and what lasts. Biomimicry is a new way of viewing and valuing nature, and it introduces an era based not on what we can extract from the natural world, but on what we can learn from it. Original design manufacturing biomaterial projects that leverage the practice of biomimicry will be discussed. Both natural and synthetic polymer platforms will be reviewed for soft tissue and hard tissue applications. Given the complexity of musculoskeletal tissue structures, the key challenge is identifying the most appropriate materials and forms for recapitulating the native function in a tissue scaffold design. The general field of biomimicry will be reviewed along with specific examples in the regenerative medicine sector

There has been considerable activity in the past year as a result of the Justice Department Investigation into the medical device industry. There has been an over reaction by many which may negatively impact future research, development and reporting of clinical outcomes. This paper will review some of these activities. A review of professional standards and guidelines has been conducted looking at health care compliance issues as they related to commercial relationships, professional medical societies, individual surgeons, and health care workers with specific focus on disclosure. Within any important issue, there are always aspects no one wishes to discuss: conflict of interest. Perception of a conflict of interest is often enough to bring about a review of activity. Overreaction has occurred as a result of government intervention into the medical device industry. Continuing medical education, professional societies by-laws, clinical/surgical publications, medical/legal exposure, product research, development and industry marketing activities have all been impacted. When professionals fail to provide a proper review process on standards and guidelines on ethical behavior they set themselves up for government oversight and restrictions on their behavior. Be informed and disclose. Know what, when and how to disclose. Protect yourself, no one else will

Crosslinking has been already used for about 80 years to enhance the longevity of polyethylene cables. The polymer alteration has been achieved with peroxide, silane or irradiation. The medical devices industry discovered the benefit of this technology for its tribological applications like hip or knee bearings in the 2000s as crosslinking improves considerably the abrasion resistance of the material. The more current methods used are Gamma and Beta irradiation. On the basis of economical (rising prices of Cobalt), environmental (the radioactive source can not be turned off), technological (low dose rate) drawbacks for Gamma respectively low penetration for Beta irradiation we decided to investigate an alternative technology: the X-Ray irradiation, which provides a homogeneous crosslinking in a relatively short time. We analyzed the wear, mechanical, thermal, oxidative and network properties of two vitamin E doped UHMWPE: first crosslinked with E-Beam, second with X-Ray. There wasn't any significant difference between the X-Ray and the E-Beam crosslinked material

Orthopedic metallic medical devices are essential in the treatment of a wide range of skeletal diseases and disabilities. However, they are often related with surgery complications due to acute prosthetic joint infections (PJI) causing devastating complications. Gallium (Ga) antibacterial activity has been recently demonstrated: in aqueous solutions, Ga ionize in a trivalent form Ga. 3+. that can replace Fe. 3+. in bacterial metabolism thus leading to bacteria death. However, it is not yet clear whether such effect is typical to Ga. 3+. release, and how this would affect longer term performance. Here we investigated Ga addition into titanium alloys using metallurgical methods. The study has confirmed that metallurgical addition of gallium even in small amounts (1–2% wt.) to titanium alloys have highly efficient antibacterial function without any visible cytostatic or cytotoxic effects. The presence of gallium within the metal matrix might ensure that antibacterial effect will persist for a long time towards multi-drug resistant S. aureus, which might not be possible if gallium or other metal are only in thin degradable coatings or similar formulations. A 5-logs decrease in CFU number was detected for alloys with 2% Ga and more after 72 h (alamar blue and CFU count assays). The alloys also show to be in vitro cytocompatible with both mature U2OS osteoblasts and progenitor pre-osteoblasts hFOB. Since gallium is metallurgically analogous to aluminium in titanium alloys, it might be used without affecting other alloy properties

Aims. This study aims to evaluate a new home medical stretching device called the Self Treatment Assisted Knee (STAK) tool to treat knee arthrofibrosis. Methods. 35 patients post-major knee surgery with arthrofibrosis and mean range of movement (ROM) of 68° were recruited. Both the STAK intervention and control group received standard physiotherapy for eight weeks, with the intervention group additionally using the STAK at home. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Oxford Knee Scores (OKS) were collected at all timepoints. An acceptability and home exercise questionnaire capturing adherence was recorded after each of the interventions. Results. Compared to the control group, the STAK intervention group made significant gains in mean ROM (30° versus 8°, p < 0.0005), WOMAC (19 points versus 3, p < 0.0005), and OKS (8 points versus 3, p < 0.0005). The improvements in the STAK group were maintained at long-term follow-up. No patients suffered any complications relating to the STAK, and 96% of patients found the STAK tool ‘perfectly acceptable’. Conclusion. The STAK tool is effective in increasing ROM and reducing pain and stiffness. Patients find it acceptable and adherence to treatment was high. This study indicates that the STAK tool would be of benefit in clinical practice and may offer a new, cost-effective treatment for arthrofibrosis. Cite this article: Bone Joint Open 2020;1-8:465–473

Summary. Metal Injection Molding could provide cost saving of about 20–50% for implantable medical device manufacturing and hence healthcare public spending. Corrosion behaviour and biocompatibility of the new manufactured alloy were studied and showed similar behaviour compared to the traditional one. Introduction. The growing trend for total joint arthroplasties could raise healthcare costs in the near future. Metal Injection Molding (MIM) is a near net shape manufacturing technology and allows the production of finite prosthesis components saving the machining step, and so resources, up to 20–50%. In order to apply such process to the production of actual devices, the bulk material have to show biocompatibility and corrosion behaviour similar to the traditional one. (ASTM F2083, ISO 21536) The aim of this work was to compare cast and forged CoCrMo alloy with the MIM one from the electrochemical point of view and cytocompatibility. Material and Methods. Metallographic observations by optical microscopy and SEM were taken to better understand the electrochemical behaviour. This evaluation was performed through potentiodynamic tests on MIM and forged (FOR) samples with polished and sandblasted surfaces (as the actual devices), in ASTM G5 cell with saline solution simulating the body environment, graphite counter electrodes and Ag/AgCl 0.15M NaCl reference electrode. Linear polarization, open circuit potential measurements and potentiostatic tests at +335 mV vs SCE were also performed during 10 days to have direct information on the corrosion resistance and ion release. Cell viability were also assessed through MTT test on polished MIM and cast (CAS) elutes, after 2 and 7 days contact periods, following ISO 10993 directions. Static ion release in H. 2. O at 2, 4 and 8 weeks were also performed. Results. MIM showed coarser grains, free of boundary carbide but with lots of circular porosities and stacking faults, in comparison with CAS structure, which presented many carbides and typical dendritic grain. Electrochemical tests exhibited analogue behaviour for the MIM and FOR CoCrMo alloys. The slightly lower passive current density and transpassive potential values obtained could be ascribed to a passive oxide layer on the MIM sample less protective than FOR CoCrMo one, as inferable from the OCP measurements, but these facts had no visible influence on polarization resistance and ion release. Such good corrosion behaviour was reflected also in static ion release results and MTT viability results, which were comparable, not only to CAS samples but also to the control medium. Conclusions. From such preliminary results MIM technology showed to have good possibility for the production of implantable medical devices with CoCrMo alloy. Corrosion resistance and biocompatibility seemed not to be affected by the different manufacturing technique. Further studies will be needed to asses also the equivalence of mechanical properties. From the metallographic observations the absence of second phases and the homogeneous microstructure suggests a better fatigue performance for this kind of alloy, even if some concerns arise from the widespread porosity observed

There are clinical situations in fracture repair, e.g. osteochondral fragments, where current implant hardware is insufficient. The proposition of an adhesive enabling fixation and healing has been considered but no successful candidate has emerged thus far. The many preclinical and few clinical attempts include fibrin glue, mussel adhesive and even “Kryptonite” (US bone void filler). The most promising recent attempts are based on phosphorylating amino acids, part of a common cellular adhesion mechanism linking mussels, caddis fly larvae, and mammals. Rapid high bond strength development in the wetted fatty environment of fractured bone, that is sustained during biological healing, is challenging to prove both safety and efficacy. Additionally, there are no “predicate” preclinical animal and human models which led the authors to develop novel evaluations for an adhesive candidate “OsStic. tm. ” based on calcium salts and amino acids. Adhesive formulations were evaluated in both soft (6/12 weeks) and hard tissue (3,7,10,14 & 42 days) safety studies in murine models. The feasibility of a novel adhesiveness test, initially proven in murine cadaver femoral bone, is being assessed in-vivo (3,7,10,14 & 42 days) in bilateral implantations with a standard tissue glue as the control. In parallel an ex-vivo human bone model using freshly harvested human donor bone is under development to underwrite the eventual clinical application of such an adhesive. This is part of a risk mitigation project bridging between laboratory biomaterial characterisation and a commercial biomaterial development where safety and effectiveness have to meet today´s new medical device requirements

Objectives. Patient-specific (PS) implantation surgical technology has been introduced in recent years and a gradual increase in the associated number of surgical cases has been observed. PS technology uses a patient’s own geometry in designing a medical device to provide minimal bone resection with improvement in the prosthetic bone coverage. However, whether PS unicompartmental knee arthroplasty (UKA) provides a better biomechanical effect than standard off-the-shelf prostheses for UKA has not yet been determined, and still remains controversial in both biomechanical and clinical fields. Therefore, the aim of this study was to compare the biomechanical effect between PS and standard off-the-shelf prostheses for UKA. Methods. The contact stresses on the polyethylene (PE) insert, articular cartilage and lateral meniscus were evaluated in PS and standard off-the-shelf prostheses for UKA using a validated finite element model. Gait cycle loading was applied to evaluate the biomechanical effect in the PS and standard UKAs. Results. The contact stresses on the PE insert were similar for both the PS and standard UKAs. Compared with the standard UKA, the PS UKA did not show any biomechanical effect on the medial PE insert. However, the contact stresses on the articular cartilage and the meniscus in the lateral compartment following the PS UKA exhibited closer values to the healthy knee joint compared with the standard UKA. Conclusion. The PS UKA provided mechanics closer to those of the normal knee joint. The decreased contact stress on the opposite compartment may reduce the overall risk of progressive osteoarthritis. Cite this article: K-T. Kang, J. Son, D-S. Suh, S. K. Kwon, O-R. Kwon, Y-G. Koh. Patient-specific medial unicompartmental knee arthroplasty has a greater protective effect on articular cartilage in the lateral compartment: A Finite Element Analysis. Bone Joint Res 2018;7:20–27. DOI: 10.1302/2046-3758.71.BJR-2017-0115.R2

Introduction. Collagen is the predominant component of extracellular matrix in various connective tissues and makes up to 25% to 35% of the whole protein content in animal bodies. Type II collagen was first introduced from chicken sternal cartilage and presents supportive function in cartilaginous tissue. Since type II collagen is the major component of cartilage in joint, this study is aiming to determine an optimal type II collagen material for the development of medical devices for articular cartilage regeneration. In order to make more effective use of underutilized food waste, type II collagens from mammalian tissue sources (porcine tracheal cartilage; auricular cartilage; articular cartilage) and marine tissue sources (cuckoo ray, blonde ray, thorn back ray, lesser spotted dogfish) were isolated through acid-pepsin digestion under 4°C and characterized by various biological, biochemical and biophysical analysis. Pepsin cleaves the telopeptide region of the collagen molecule and pepsin treated collagen extraction ensures higher collagen yield. Telopeptide-free collagen reveals cytocompatibility, biodegradability and lower toxicity. The number and size of collagen chains were revealed by SDS-polyacrylamide gel electrophoresis. Intermolecular crosslinking density was quantified by Ninhydrin assay. Thermal stability was tested by differential scanning calorimetry (DSC) and enzymatic degradation was assessed by collagenase assay. Human chondrocytes were seeded on to collagen sponges at a density of 30,000 cells per sponge. Cell morphology (DAPI/ Rhodamine Phalloidin), viability(LIVE/DEAD®), proliferation(PicoGreen®) and metabolic activity (alamarBlue®) were analysed. Quantitative morphometric analysis was carried out using ImageJ software. Conclusion. Porcine articular cartilage and cartilaginous fishes yield high purity type II collagen. Type II collagen isolated from cartilaginous fishes exhibited similar crosslinking density and thermal stability. Among various porcine cartilaginous tissues, articular cartilage was the most resistant to enzymatic degradation and female trachea exhibited the highest cross-linking density. The biological, biochemical and thermal properties of type II collagen are dependent on the tissue and gender from which the collagen was extracted

Designs of medical devices are tested for their mechanical behaviour, ability to transfer the load that is normally bore by the healthy tissue, and prove of the resistance to fatigue. The virtual testing in silico is widely accepted technique based on three sets of input data – geometry is normally obtained from CT or MRI scan as well as the tissue density that is translated into mechanical properties of the tissue. The virtual behaviour of the system is controlled by set of constrains accordingly while the third set of data consist of the load that system normally transfers through the load-bearing tissue. The magnitude and character of the load is highly dependent on the physical activity, external loads, physical condition of the subject and its specific factors such as gender, health condition, etc. Most of the published simulations use estimated simplified loads, which barely simulate the real behaviour of the system. The evaluation of the spinal load published some years back estimated a normal (N) and shear force (S) accompanied by the flexing moment (M). Due to lack of experimental possibility we used these data to test the biomechanical response of the lumbar segment with isotropic material models of all tissues. Then we investigated the possibility to evaluate muscular forces and their recruitment. It is a complex task and even today it is not possible to measure directly in vivo all muscular forces contributing to the movement. The musculo-skeletal system is a statically indeterminate system. The forces can be solved by means of computational modelling based on the measured trajectories of the body motion and additional optimization functions combined with static equations. The trajectories were recorded by the fast camera system in our motion laboratory and consequently exported into an open simulation software that uses a generic skeleton with around two hundreds muscle fascicles. The skeleton was scaled to correspond to our subject's anthropometric data and further scaling to mock-up the generic vertebrae was performed to eliminate discrepancies between the generic and subject's bones. Once these adjustments were done a kinematics and inverse dynamics modules were engage with selected objective function controlling the muscular recruitment that the max. relative muscular force is as small as possible. The 84 muscular forces acting on the segment were exported to a text file in APDL language and uploaded in the Finite Element (FE) database. The results of FE analysis were compared to the results obtained earlier using N,S,M load [1]. The comparison between the two models shows that the results of segment's total displacement was reduced by 36 percent compared to initial results. The stress and stress intensity increased six times. The identical model with orthotropic material showed reduced displacement by 80 percent and the stress and stress intensity was reduced by 60 percent compared to initial results

Aim. In private healthcare facilities, the access to a specialized infectious disease (ID) advice is difficult. More, the lack of traceability is problematic and harmful for treatment and follow-up. We have tested an information technology (IT) application to improve medical transmission and evaluate an interdisciplinary ID activity. Methods. In November 2015, three ID physicians (IDP) created an interdisciplinary activity, visiting patients and giving phone advices among ten private healthcare facilities. They are members of the complex bone and joint infection unit of the community hospital where they are attached. Since September 2016, each advice was prospectively recorded on a protected online information system. These data are available for consultation and modification by the three IDP. It is the first descriptive analysis of this database. Results. From September 2016 to February 2017, 887 advices from 573 inpatients were collected. Median age was 69 years old and 56% of patients were male (n=320). Comorbidity was notified in 329 patients (57%): presence of a medical device (n=154), active neoplasia (n=76), mellitus diabetes (n=38) and renal failure (n=38) were the most common. Patients were hospitalized in a surgery unit in 49% of cases and of which 69% was the orthopaedic unit. By frequency, type of infection was prosthetic joint (n=111) and osteosynthesis device infection (n=67), urinary tract infection (n=57), skin infection (n=44), and catheter device infection (n=43). The presence of multidrug resistant bacteria was notified in 63 patients. Antibiotics were already administered before the first advice in 62% of patients. Advices were given after a medical consultation in the clinic in 353 cases (40%) and after a phone call with the physician in charge of the patient in 523 cases (60%). Antibiotics were disrupted or not introduced for 126 advices (14%), introduced for 133 advices (15%), modified in 337 advices (38%) and maintained unchanged in 291 advices (33%). New evaluation was effective for 171 patients (30%). Multidisciplinary meeting was requested for 54 patients. Conclusion. Use of an information system for interdisciplinary and multisite ID activity has permitted with a better traceability to improve management of these septic patients, facilitate storage and transmission of medical information. It is a first overview of ID activity in private healthcare facilities and these tools appear essential in the development of such activity and for public health policy

Aims

To explore the clinical efficacy of using two different types of articulating spacers in two-stage revision for chronic knee periprosthetic joint infection (kPJI).

Aims

Orthopaedic surgery requires grafts with sufficient mechanical strength. For this purpose, decellularized tissue is an available option that lacks the complications of autologous tissue. However, it is not widely used in orthopaedic surgeries. This study investigated clinical trials of the use of decellularized tissue grafts in orthopaedic surgery.

Aims

Research on hip biomechanics has analyzed femoroacetabular contact pressures and forces in distinct hip conditions, with different procedures, and used diverse loading and testing conditions. The aim of this scoping review was to identify and summarize the available evidence in the literature for hip contact pressures and force in cadaver and in vivo studies, and how joint loading, labral status, and femoral and acetabular morphology can affect these biomechanical parameters.

Introduction. The Birmingham Hip Resurfacing (Smith & Nephew London, UK) is the most popular hip resurfacing (HR) in the UK. However, it is now subject to two Medical Device Alerts (MDA) from the Medicines and Healthcare products Regulatory Agency (MHRA). Patients/Materials & Methods. A cross-sectional survey of primary metal-on-metal hip procedures recorded on the National Joint Registry for England, Wales and Northern Ireland (NJR) until 5. th. November 2013 was performed. Cost-analysis was based on an algorithm for surveillance of HR at a tertiary referral centre and followed previous MHRA guidance. NIHR NHS Treatment costs were used. The local protocol encompassed: patient outcome scoring (Oxford hip score), blood metal ion measurement (cobalt, chromium), cross-sectional imaging (MRI) and discussion at an internet-enabled multidisciplinary team meeting (iMDT) in addition to routine hip surveillance. Results. A total of 33996 patients have Hip Resurfacings in the UK. 18478 have BHR and 9457 are female or small men. Costs:. Cobalt and Chromium levels £34.64. Single site MRI scan £438.91. Review of medical notes is £97.98. New Patient Appointment £137. Every patient requires at least 1 set of blood tests, an MRI and discussion in iMDT in our unit at a minimum cost of £571.53. This excludes clinic appointments; repeat testing, or costs of revision surgery and litigation. Total minimum cost to NHS £5.4 million. Discussion. It is important to not ignore nationally delivered guidance and therefore this patient group now requires comprehensive follow up as described by the MHRA. Other HR devices may now need to be considered to require further follow-up with inherently increased costs to the NHS. Conclusion. We recommend a streamlining of review via regional iMDTs in order to effectively manage MDA's and minimise potential costs

Aims

Metal-on-metal hip resurfacing (MoM-HR) has seen decreased usage due to safety and longevity concerns. Joint registries have highlighted the risks in females, smaller hips, and hip dysplasia. This study aimed to identify if reported risk factors are linked to revision in a long-term follow-up of MoM-HR performed by a non-designer surgeon.

Aims

Periprosthetic fracture and implant loosening are two of the major reasons for revision surgery of cementless implants. Optimal implant fixation with minimal bone damage is challenging in this procedure. This pilot study investigates whether vibratory implant insertion is gentler compared to consecutive single blows for acetabular component implantation in a surrogate polyurethane (PU) model.

Aims

Fungal periprosthetic joint infections (PJIs) are rare, but their diagnosis and treatment are highly challenging. The purpose of this study was to investigate the clinical outcomes of patients with fungal PJIs treated with two-stage exchange knee arthroplasty combined with prolonged antifungal therapy.

Aims

The risk of mechanical failure of modular revision hip stems is frequently mentioned in the literature, but little is currently known about the actual clinical failure rates of this type of prosthesis. The current retrospective long-term analysis examines the distal and modular failure patterns of the Prevision hip stem from 18 years of clinical use. A design improvement of the modular taper was introduced in 2008, and the data could also be used to compare the original and the current design of the modular connection.

Aims

The Birmingham Hip Resurfacing (BHR) was introduced in 1997 to address the needs of young active patients using a historically proven large-diameter metal-on-metal (MoM) bearing. A single designer surgeon’s consecutive series of 130 patients (144 hips) was previously reported at five and ten years, reporting three and ten failures, respectively. The aim of this study was to extend the follow-up of this original cohort at 25 years.

Aims

Although the Fitmore Hip Stem has been on the market for almost 15 years, it is still not well documented in randomized controlled trials. This study compares the Fitmore stem with the CementLeSs (CLS) in several different clinical and radiological aspects. The hypothesis is that there will be no difference in outcome between stems.

Aims

The primary aim of this study is to assess the survival of the uncemented hydroxyapatite (HA) coated Trident II acetabular component as part of a hybrid total hip arthroplasty (THA) using a cemented Exeter stem. The secondary aims are to assess the complications, joint-specific function, health-related quality of life, and radiological signs of loosening of the acetabular component.

Aims

This study investigated vancomycin-microbubbles (Vm-MBs) and meropenem (Mp)-MBs with ultrasound-targeted microbubble destruction (UTMD) to disrupt biofilms and improve bactericidal efficiency, providing a new and promising strategy for the treatment of device-related infections (DRIs).

INTRODUCTION. Retrieval analysis is an important aspect of medical device development. Examination of retrieved devices allows device developers to close the design loop, understand the performance of devices, and validate assumptions made and methods used during preclinical testing. We provide an overview of the implant retrieval analysis performed at the Implant Research Center at Drexel University on reverse total shoulder systems retrieved after short to medium term implantation. METHODS. We have examined 18 reverse total shoulders, retrieved at revision surgery after short to mid-term implantation (average 1.4 years, maximum 3.3 years). The average age at revision was 71 years old (st dev 11 years). Our evaluations included analysis of glenosphere bearing surface damage, evaluation of tribocorrosion at the modular junctions, visual assessment of polyethylene humeral bearing surface damage, quantitative analysis of polyethylene wear. RESULTS and DISCUSSION. We observed that polyethylene wear of the humeral bearing surface (mode I) is limited in the short to medium term and that wear and damage of revised devices are dominated by unintentional contact and impingement of the inferior rim of the bushing (mode II damage). This was in agreement with a previously published analysis of a smaller cohort (Figure 1). Scratching and damage of the glenosphere was a common observation, particularly in patients with a history of instability. The observed increase in glenosphere roughness was similar to that reported in association with hip dislocation (Figure 2). Damage at the modular junctions was limited and dominated by fretting rather than corrosive damage. Mild to moderate fretting was commonly observed at the interface between the glenosphere and metaglene (Figure 3). These observations provide an increased understanding of device performance and potential failure modes. Further studies will be necessary to characterize the long term performance of reverse total shoulder systems

Aims

To investigate the efficacy of ethylenediaminetetraacetic acid-normal saline (EDTA-NS) in dispersing biofilms and reducing bacterial infections.

Development of antibacterial surfaces or coatings to prevent bacterial adhesion and hence colonization of implants and biofilm formation is an attractive option, in order to reduce the tremendous impact of implant-related infections associated with modern surgery. To overcome the lack of in vivo and clinical models, able to evaluate the performance of anti-adhesive coatings, we designed an in vitro experimental setting that allows to quantitatively evaluate the ability of a coating to reduce bacterial adhesion on a given surface; this model may efficiently serve as a surrogate endpoint to validate anti-adhesive medical devices and compounds. Here we report the results the evaluation of the anti-adhesive properties of a patented, fast-resorbable hydrogel coating, (“Defensive Antibacterial Coating”, DAC). Sterile sandblasted titanium discs of approximately 5cm. 2. surface area were used as substrates for bacterial adhesion. The gel was prepared as follows: syringes prefilled with 300 mg of DAC powder (Novagenit Srl) were reconstituted with 5 ml of sterile water to obtain a hydrogel with a DAC concentration of 6%. Two experiments were conducted. In the first, 200 mg of hydrogel were homogenously spread on the surface of titanium disc, with the spreading device provided by the manufacturer. Both coated and uncoated substrates (controls) were overlaid with a standardized inoculum (10. 8. CFU/ml) of a wild methicillin-resistant Staphylococcus aureus strain, previously isolated from a peri-prosthetic joint infection, for 15, 30, 60 and 120 minutes. Afterwards, non-adherent bacteria were removed by rinsing with sterile saline. The remaining adhered cells were seeded on agar plates for CFU count. In the second experiment, the discs were first inoculated with bacterial cells followed by a treatment with the hydrogel and bacterial count as described above. Ten discs were used for each condition and each time interval (total 160 discs). The adhesion density of S. aureus on titanium discs pre-treated with DAC was significantly lower than that observed on untreated controls at each time point. In particular, the average number of adherent bacteria at 15, 30, 60 and 120 minutes of incubation, was respectively reduced by 86.8%, 80.4%, 74.6% and 66.7%, compared to controls (p<0.001). DAC treatment of discs with previously adhered S. aureus reduced bacterial adhesion, at 15, 30, 60 and 120 minutes of incubation, by, respectively, 84.0% (p<0.05), 72.8%, 72.3% and 64.3% (p<0.001), compared to untreated controls. Our results shows that DAC, “Defensive Antibacterial Coating”, has anti-adhesive properties that allow to reduce bacterial adhesion on a sanded titanium surface by more than 80%, even in the presence of remarkably high bacterial loads (10. 8. CFU/ml), of multi-resistant bacteria (MRSA) and even in the case of previous contamination. Providing anti-adhesive properties to a surface with a fast-resorbable coating may be a safe option to protect inorganic and organic surfaces and biomaterials. Those observation could be the pre-requisite for its in vivo application

Objectives. High failure rates of metal-on-metal hip arthroplasty implants have highlighted the need for more careful introduction and monitoring of new implants and for the evaluation of the safety of medical devices. The National Joint Registry and other regulatory services are unable to detect failing implants at an early enough stage. We aimed to identify validated surrogate markers of long-term outcome in patients undergoing primary total hip arthroplasty (THA). Methods. We conducted a systematic review of studies evaluating surrogate markers for predicting long-term outcome in primary THA. Long-term outcome was defined as revision rate of an implant at ten years according to National Institute of Health and Care Excellence guidelines. We conducted a search of Medline and Embase (OVID) databases. Separate search strategies were devised for the Cochrane database and Google Scholar. Each search was performed to include articles from the date of their inception to June 8, 2015. Results. Our search strategy identified 1082 studies of which 115 studies were included for full article review. Following review, 17 articles were found that investigated surrogate markers of long-term outcome. These included one systematic review, one randomised control trial (RCT), one case control study and 13 case series. Validated surrogate markers included Radiostereometric Analysis (RSA) and Einzel-Bild-Röntgen-Analyse (EBRA), each measuring implant migration and wear. We identified five RSA studies (one systematic review and four case series) and four EBRA studies (one RCT and three case series). Patient Reported Outcome Measures (PROMs) at six months have been investigated but have not been validated against long-term outcomes. Conclusions. This systematic review identified two validated surrogate markers of long-term primary THA outcome: RSA and EBRA, each measuring implant migration and wear. We recommend the consideration of RSA in the pre-market testing of new implants. EBRA can be used to investigate acetabular wear but not femoral migration. Further studies are needed to validate the use of PROMs for post-market surveillance. Cite this article: T. T. Malak, J. A. J. Broomfield, A. J. R. Palmer, S. Hopewell, A. Carr, C. Brown, D. Prieto-Alhambra, S. Glyn-Jones. Surrogate markers of long-term outcome in primary total hip arthroplasty: A systematic review. Bone Joint Res 2016;5:206–214. DOI: 10.1302/2046-3758.56.2000568

Introduction. We have previously demonstrated that peroxide crosslinked vitamin E-blended UHMWPE maintains its clinically-required wear and mechanical properties [1]. This material can potentially be used as an irradiation-free bearing surface for TJA. However, using organic peroxides in medical devices requires a thorough examination of tissues in contact with the implant. For this study we crosslinked polyethylene using five times the needed concentration of peroxide (2,5-Dimethyl-2,5-di(t-butylperoxy)-hexyne-3 or P130), followed by implantation to determine implant biocompatibility, and pre and post implant peroxide residual contents. Methods. The study was performed after institutional approval following ISO standard 10993–6. Study groups: not crosslinked (0.2 (1050) VE), crosslinked (0.2 VE (1050)/5% P130) and crosslinked-high temperature melted (HTM) (0.2 VE (1050)/5% P130). Materials were blended and consolidated, machined (2.5 diameter × 2.5 cm height), sterilized and implanted in the dorsum New Zealand white rabbits. Pre and post implantation FTIR was performed. Two samples were implanted in each rabbit; n=6 samples were included for each group. After 4 weeks, samples were explanted, analyzed using FTIR, and subcutaneous tissues processed for histological analysis. Results. FTIR absorbances at 914cm. −1. , 1169cm. −1. , and the OH absorbance at 3450cm. −1. showed differences between materials (Fig 1A). There was a significant increase in the absorbance at 914 for the non-crosslinked and crosslinked samples after explantation (p = 2.77E–17, p = 4.22E–23, Fig 1B). There was a significant decrease in all peroxide related absorbances after explantation for the crosslinked and HTM samples (p < 0.05, Fig 1B). Before implantation, these absorbances were significantly higher in the crosslinked and crosslinked/HTM samples than those in the non crosslinked sample (p<0.05, Fig 2A). Peroxide related absorbances of the crosslinked sample were also significantly higher than those of the crosslinked/HTM sample (p<0.05, Fig 2A). After explantation, the crosslinked samples had significantly higher absorbances than both the non crosslinked and crosslinked/HTM samples (p < 0.05, Fig 2A). All peroxide related absorbances of the crosslinked/HTM samples were significantly higher than those of the non crosslinked sample (p < 0.05, Fig 2A). The non crosslinked sample showed no significant differential between these absorbances at implantation and after retrieval. The crosslinked sample had the largest differential between the total peak absorbances before implantation and retrieval at 914cm. −1. The crosslinked/HTM samples had the largest differential between the total peak absorbances before and after implantation for both 1169cm. −1. and the OH absorbances (Fig 2B). All explants were recovered after four weeks in vivo (Fig 3A). No difference was found in the histological analysis of the tissue characterized by a synovial-like lining with signs of fibrosis around the implants (Fig 3B). Discussion. The main challenge of this study was identifying pre and postoperative implant peroxide residual peaks via FTIR. We wanted to ensure that peroxide was present in implants before implantation, to ensure their elution into tissues. Conclusions. Peroxide crosslinked polyethylene stabilized with vitamin E can potentially be used as an alternate bearing surface. Irradiation-free processing could result in cost-effectiveness and more accurate cross-linking of polyethylene implants

Abstract Detail. Interim results on a prospective, randomised, single-blinded pilot study to compare implant alignment using a patient-matched cutting guide versus a computer-assisted navigation system following total knee arthroplasty. Purpose of Study. To compare implant alignment using a patient-matched cutting guide (Visionaire) versus a computer-assisted navigation system (CAS) following total knee arthroplasty (TKA). Description of methods. Ethics approval was sought and granted by the South African Medical Association Research Ethics Committee. Patient consent for participation was obtained. Patients were randomized to TKA using Visionaire or CAS. Mechanical alignment was evaluated pre-operatively and at 3 months with a full leg X-Ray. Operative and post-operative parameters relating to resource utilization were captured. Clinical status according to the Knee Society Clinical Rating System (KSCRS) was assessed pre-operatively and at 3 months. Adverse events were noted. An independent Contract Research Organisation was used to monitor the site. Summary of results. Ten unique patients were enrolled, of whom 5 were randomized to Visionaire and 5 to CAS. Two patients in the Visionaire group have not yet reached their 3-month assessment. No significant difference in mechanical alignment between the 2 groups at 3 months was observed. The median duration of surgery was significantly shorter for the patient-matched cutting guide group across all assessed parameters (theatre time: 117 versus 150 minutes, p=0.009; operative time: 85 versus 108 minutes, p=0.0088; tourniquet time: 73 versus 99 minutes, p=0.009; and anaesthetist time: 117 versus 150 minutes, p=0.009). No other significant differences in operative or post-operative cost-drivers were noted between the 2 groups. No significant difference in KSCRS scores between the 2 groups at 3 months was observed. Two adverse were reported, one in each group, both unrelated to the medical devices, and both of which have resolved. Conclusion. While implant alignment appears consistent and comparable in both groups at 3 months, the median duration of surgery was significantly shorter for the Visionaire group. DISCLOSURE: Assistance and funding was received from Smith & Nephew

Aims

Routinely collected patient-reported outcome measures (PROMs) have been useful to quantify and quality-assess provision of total hip arthroplasty (THA) and total knee arthroplasty (TKA) in the UK for the past decade. This study aimed to explore whether the outcome following primary THA and TKA had improved over the past seven years.

S epidermidis and P aeruginosa are recognised major biofilm pathogens in medical device contamination and chronic wounds. Within biofilms, bacteria are enclosed in a polymeric matrix that cements them to each other and to the surface and protects them by increasing resistance to host immunity, antibiotics and biocides. Staph and pseudomonas spp biofilm were grown on glass coupons for 48 hours and the coupons randomly inserted into the wound model for 24 hours and subjected to TNP and the following:. No instillation. 0.1% w/v formulated hypocholorous acid (FHA) instillation. Saline instillation. Betadine instillation. Betadine and saline instillations were for 30 minutes, while FHA was for three minutes, every eight, four and two hours per day. The biocides were at sub-lethal concentrations. The coupons were then extracted to avoid damaging the biofilms and effect of TNP was assessed by colony forming units and electron microscopy. The results show that lower frequency of instillation did not have significant effect on bacterial load for both types of bacteria. Increase in frequency of instillations resulted in no growth of pseudomonas while increase in frequency of instillations resulted in a significant decrease in growth of staph spp. Frequent flushing of the wound model resulted in a loss of biofilm bacteria for both Pseudomonas and Staph epi. The biocides combined with TNP were more effective in killing Pseudomonas compared with Staph epi

Rapid manufacturing using laser beam and/or electron beam has been applied to fabrication of artificial hip and knee joints in quite recent years. In the electron beam melting (EBM) method, the high energy electron beam effectively melts the metal powder without creating flaws such as porosities or inclusions of oxide particles during building. Thus it is found that EBM technique for rapid manufacturing of artificial hip and knee joints processes a higher possibility as the next-generation methodology for fabrication of the medical devices such as hip and knee joints. In the present study, we focus on the EBM technique. The microstructures and mechanical properties of Co-29Cr-6Mo alloy with C and N additions, produced by using EBM method, were studied using X-ray diffraction, electron back scatter diffraction, transmission electron microscope (TEM), Vickers hardness tests, and tensile tests, focusing on the influences on the build direction and the various heat treatments after build. It is found that the microstructures for the as built specimens were changed from columnar (Fig. 1a) to eqiaxed grain structure (Fig. 1c) with average grain size of approximately 10–20 μm due to the heat treatment employing the reverse transformation from a lamellar (hcp + Cr. 2. N) phase to an fcc phase. Our results will contribute to the development of biomedical Ni-free Co–Cr–Mo–N-C alloys, produced by EBM method, with refined grain size and good mechanical properties, without requiring any hot workings. Fig. 1 Inverse pole figure (IPF) maps of microstructure of samples produced by EBM method, taken by EBSD. (a) as-built, (b) after aging treatment, (c) after reverse transformation heat treatment (RT-HT)

Total joint arthroplasty is a safe and effective procedure as an end-stage treatment for arthritis. In the case of hip replacement mean patient age has decreased from sixty-eight to sixty-five years over the past eight years, raising concerns over implant longevity and the complications that occur in association with revision surgery. The dominant mode of failure of total joint replacements is aseptic loosening, which in many cases is caused by the reaction of bone to the presence of implant debris. In an attempt to increase implant longevity, bearing surfaces that minimize the volume of debris generated from the articular surface are being developed. Ultra- high molecular weight polyethylene, which has been the mainstay of arthroplasty, changing the material with which the polyethylene articulates has also been addressed in an effort to further improve wear characteristics. Oxinium is the brand family name of a material used for replacement joints manufactured by the reconstructive orthopedic surgery division of medical devices company Smith & nephew. It consists of a Zirconium alley metal substrate that transitions into a ceramic Zirconium oxide outer surface. The ceramic surface is extremely abrasion resistant compared to traditional metal implants such as cobalt chromium. It also has a lower coefficient of friction against ultra-high molecular weight polyethylene(UHMWPE), The typical counter face material used in total joint replacements. These two factors likely contribute to the significantly lower UHMWPE wear rates observed in simulator testing. Reducing UHMWPE wear is thought to decrease the risk of implant failure due to osteolysis. All ceramic material can have a similar effect in reducing wear, but are brittle and difficult to manufacture. The metal substrate of oxinium implants makes component easier to manufacture and gives them greater toughness(a combination of strength and ductility). In essence, this technology combines the abrasion resistance and low friction of a ceramic with the workability and toughness of a metal

Millions of medical devices made of synthetic or modified natural materials all trigger a similar reaction—the foreign body reaction. Biocompatibility, for materials that pass routine cytoxicity assays, is largely associated with a mild foreign body reaction. I.e. a thin, avacular, collagenous, non-adherent foreign body capsule. The implant is incorporated into a dead-zone of acellular scar. The contemporary tissue engineering paradigm would suggest that synthetic polymers and scaffolds lacking cellular, biomolecule or biomimetic elements will give this same fibrotic, avascular healing reaction. In this talk, a synthetic biomaterial will be described that readily integrates into tissue and may stimulate spontaneous reconstruction of tissue. The material is fabricated by a process called sphere-templating and it can be made from many synthetic polymers including hydrogels, silicones and polyurethanes. All pores are identical in size and interconnected. Studies from our group have shown optimal healing (as suggested by extensive vascularity and minimal fibrosis) for spherical pores of 30–40 m size. The integrative healing noted is independent of biomaterial. Similar results are observed with sphere-templated silicone rubber and pHEMA hydrogel. In addition, surface chemical modification of the hydrogel with carbonyl diimidazole, or immobilisation on the hydrogel of collagen I or laminin did not change the healing response. Also, good healing results have been seen upon implantation in skin (subcutaneous, percutaneous), heart muscle, sclera, skeletal muscle, bone and vaginal wall. We consistently find the pore spaces heavily populated by monocytic cells that stain for macrophage cell surface markers. However, at long implantation times (16 or more weeks), the ability to stain for macrophage surface markers decreases. It could be possible that these cells populating the implants are differentiating into other tissues. Thus, such materials may represent a path to cell-free tissue engineering. Others have seen similar healing results, via completely different materials strategies, generally involving biological molecules. The in vivo results from our group and related results from other groups suggest we are on the cusp of a revolution in healing, biomaterials integration and tissue reconstruction. Also, the boundaries between biomaterials and tissue engineering continue to blur

Over the past 40 years information from large institutional total joint registries have aided in patient clinical care and follow-up efforts, have helped drive improvements in clinical practice, and have been a powerful tool for generating research studies on large well documented populations of patients. Still, these efforts are limited in that they are expensive, usually reflect a single institutional experience, and results can be biased by the larger volumes or experience at the typically large academic centers which have such registries in place. National registry efforts in other countries including Scandinavia, Australia, and the UK have resulted in improved outcomes and a decreased number of revision procedures by a combination of early identification and withdrawal of poorly performing implants, altered surgical techniques, implant choices and behaviors by surgeons, changes in practices by hospitals, and modification in requirements and incentives by payors and regulatory agencies. The American Joint Replacement Registry (AJRR) is a collaborative multi-stakeholder, independent, not-for-profit 501 c3 organisation established in 2009 for data collection and quality improvement initiatives relating to total hip and knee arthroplasty. AJRR is a national registry effort with the goal of enrolling more than 90% of the over 5,000 hospitals performing nearly 1 million hip and knee arthroplasties each year in the US. AJRR is supported by contributions from the American Academy of Orthopedic Surgeons (AAOS), the American Association of Hip and Knee Surgeons (AAHKS), the Hip Society, the Knee Society, Health Insurers, Medical Device Manufacturers, and individual orthopaedic surgeons via designated contributions through the Orthopedic Research and Education Foundation (OREF). The overarching goal of AJRR is to improve arthroplasty care for patients through the collection and sharing of data on all primary and revision total joint replacement procedures in the U.S. The mission of the registry is to enhance patient safety, and improve the value of arthroplasty care. This will be accomplished by providing national benchmarks for implant, surgeon and hospital performance which serves to modify behaviors thereby decreasing the revision burden, improving outcomes and reducing costs. From the time of incorporation in 2009 up to October 2013 the AJRR has secured the participation of 218 hospitals in 47 different states in the formal enrollment process, and have level one data submission from more than 100 institutions on over 63,000 hip and knee procedures. In addition to publicly available annual reports, confidential specific individual reports for hospitals, surgeons and manufacturers will be available by subscription with an option for future confidential online direct data queries by an individual or entity regarding their own individual performance compared to national benchmark values. In summary, registry studies have provided a rich source of information for improving arthroplasty care over the past four decades, with the emergence and increasing interaction of national registries a major factor in current efforts to increase both the quality and value of the health care of entire populations. The development, support and continued expansion of a national registry in the US must remain a central focus if we wish to improve as much as possible the arthroplasty care provided to all patients in our country

Surgeons acquire knowledge from a variety of sources that include textbooks, journals, the attendance at scientific meetings and workshops, from the internet, from continuing medical education (CME) programs and from informal corridor discussions with colleagues. Surgeons also rely heavily on the information that is provided by the manufacturers and distributors of implantable surgical devices. Advertisements in journals and on the internet are frequently published for surgical products where there are claims by manufacturers of clinical and scientific fact. Also it is the case that the pictorial (photographic) content of these advertisements can be of a nature that might lead the reasonable observer into error. Patients and their Surgeons, both as consumers, will frequently rely heavily on the available information when exercising choice. In the event it is particularly important that manufacturers avoid the publication of promotional information that might be misleading or deceptive, as consumers can be greatly influenced by marketing material and by the representations made. Though the manufacturers of drugs have frequently been accused of misleading consumers, the claims made by surgical device manufacturers have escaped any more than minor criticism. The author discusses the question of what might or might not be misleading or deceptive conduct. Evidence is presented to support the view that there is a very fine line that separates puffery from conduct where there is a real or not too remote chance that might lead another into error. The Australian law of misrepresentation is complicated and includes two sources of law. These are the general law which is an amalgam of general law and equity rules and the Trade Practices Act s52 which is mirrored in the Fair Trading Acts of each State and Territory. The author reviews this law as it effects the medical devices industry. It is evident that there are lessons to be learned that include the need for greater diligence by surgical implant manufacturers when substantiating their claims and greater vigilance among members of the medical profession, and other consumers, when exposed to promotional material

The primary objective of this study was to evaluate the performance of the Acrobot. ®. Sculptor system in achieving a surgical plan for implantation of unicompartmental knee prostheses, compared with conventional surgery. The Acrobot. ®. Sculptor is a novel hands-on medical device, consisting of a high speed cutter mounted on a robotic device which the surgeon holds and directs. A prospective, randomised, double-blind (patient and evaluator), controlled versus conventional surgery study was undertaken and has been fully reported in Journal of Bone and Joint Surgery (British), 88-B. All (13 out of 13) of the Acrobot. ®. cases were implanted with tibio-femoral alignment in the coronal plane within ±2° of the planned position, while only 40% (six out of 15) of the conventionally performed cases achieved this level of accuracy. There was also a significant enhancement in the extent of post-operative improvement, as measured by American Knee Society (AKS) Scores at six weeks, in the cases implanted with the Acrobot. ®. The difference between type of surgery is statistically significant (p=0.004, Mann-Whitney U test). Operating time (skin to skin) is higher in Acrobot treated subjects, but the difference between the two types of surgery fails to reach significance. The Acrobot. ®. System was found to significantly improve both accuracy and short term outcome in this investigation. By permitting the creation of bone surfaces that can be machined by means other than an oscillating saw, the Acrobot. ®. System paves the way for novel implant designs to be developed, facilitating bone conserving arthroplasty in the knee, hip and spine with a new generation of even less invasive but more reliable procedures

Introduction. Total knee arthroplasty (TKA) prostheses are semi-constrained artificial joints. A well-functioning TKA prosthesis should be designed with a good balance between stability and mobility, meaning the femorotibial constraint of the artificial joint should be appropriate for the device's function. To assess the constraint behavior of a TKA prosthesis, physical testing is typically required, and an industrial testing standard has been developed for this purpose [1]. Computer simulation has become increasingly useful in many industries, including medical device research and development where finite element analysis (FEA) has been extensively used in stress analysis and structural evaluation. This study presents an FEA-based simulation to evaluate the femorotibial constraint behavior of TKA prosthesis, and demonstrated the effectiveness of the method by validating through physical testing. Methods. A Cruciate Retaining (CR) TKA prosthesis design (Optetrak Logic CR, Exactech, USA) was used in this study. CAD models of the implants assembled at 0° of flexion were used for the simulation. Finite element models were generated using with all materials assumed linear elastic. Boundary conditions were set up according to the ASTM F1223 standard (Figure 1). The tibial baseplate was fixed distally. A constant compressive force (710 N) was applied on the femoral component. Nonlinear Surface-Surface-Contact was defined at the femorotibial articulating surfaces. Coefficient of friction was determined from physical test. The femoral component was driven under a displacement-controlled scheme to slide along the anterior-posterior (AP) direction on the tibial insert. At each time step, constraint force occurring at the articulating surface was derived from the reaction force at the distal fixation of the tibial baseplate. A nonlinear FEA solver (NX Nastran SOL601, Siemens, USA) was used to solve the simulation. In addition, five samples of the prostheses were physically tested, and the results were compared with the simulation. Results. The simulation successfully captured the movement of contact location and pressure along the movement of the femoral component (Figure 2). The force-displacement curve predicted by the simulation exhibited a very close hysteresis loop profile as the results of physical testing (Figure 3). Using the curve slope from 0 to 5 mm to characterize the linear constraint, the simulation predicted 45.7 N/mm anteriorly and 36.4 N/mm posteriorly, which are less than 10% different from the physical testing results (46.4 N/mm anteriorly and 39.6 N/mm posteriorly). Discussion/Conclusion. This study demonstrated that the simulation was able to closely predict the femorotibial constraint behavior of the TKA prosthesis under ASTM F1223 testing. The simulation results resembled the physical testing results not only in the general curve profile but also in the magnitude of slope values. The increased difference at the far anterior region could be related to the fact that no material nonlinearity was currently considered, which could be improved in future studies. A validated simulation method could be very useful in TKA prosthesis design. Since no physical prototypes are required, design evaluation and optimization can be achieved in a much easier and faster manner

Numerous in vitro studies have utilised bone models for the assessment of orthopaedic medical devices and interventions. The drivers for this usage are the low cost, reduced health concerns and lower inter-specimen variability when compared to animal or human cadaveric tissues. Given this widespread exploitation of these models the push for their use in the assessment of spinal augmentation applications would appear strong. The aim of the research was to investigate the use of surrogate-bone vertebral models in the mechanical assessment of vertebroplasty. Nine surrogate-bone whole vertebral models with an open-cell trabeculae configuration were acquired. Initial μCT scans were performed and a bone marrow substitute with appropriate rheological properties was injected into the trabeculae. Quasistatic loading was performed to determine the initial fracture strength in a manner previously used with human cadaveric vertebrae. Following fracture, vertebroplasty was undertaken in which there was a nominal 20% volume fill. Following augmentation the VBs were imaged using uCT and then subjected to an axial load using the same protocol. The surrogate models had a substantially thicker cortex than that of human osteoporotic vertebrae. During compression, the surrogate-bone models did not exhibit the characteristic ‘toe-region’ observed in the load-deformation profile of cadaveric vertebrae. The mean initial and post-augmentation failure strength of the surrogate vertebrae were 1.35kN ± 0.15kN and 1.90kN ± 0.68kN, respectively. This equates to a statistically significant post-vertebroplasty increase by a factor of 1.38. In comparison with human osteoporotic bone, no significant difference was noted in the relative increase in fracture strength between the artificial and human VB following augmentation. Despite the apparent equivalence of the strength and stiffness of the artificial vertebrae compared to that of the cadaveric specimens, there are significant differences in both pre- and post augmentation behaviour. In particular, the load-deformation curve shows significant differences in shape particularly at the toe end and in post failure behaviour. There are also issues surrounding where the marrow and cement flows during the injection process thus affecting the final distribution of the cement

Replacement of damaged or diseased tissues with permanent metal implants based on stainless steel, cobalt chrome and titanium alloys has been at the forefront of classical biomaterials research and the orthopaedic medical device industry for decades. Biodegradable polymers have also reached the market but often have limited capacity in load bearing orthopaedic applications due to their low stiffness and poor mechanical properties. The development of biodegradable metals based on magnesium (Mg) could be heralded as a major breakthrough in the field of orthopaedic surgery. Degradable implants eliminate the time and cost associated with a secondary surgery to remove hardware, and reduces the period the implant is exposed to instability, fibrous encapsulation, stress shielding and inflammation. The metabolism of Mg and its excretion via the kidneys is a natural physiological process that is well understood, however, controlling the rapid degradation of Mg biomaterials in vivo is a major challenge yet to be resolved for the safe and effective use of Mg in orthopaedic implants. In this study, we describe a novel manufacturing method for fabricating Mg/Mg alloy implants, as well as the development of an in vitro method for screening Mg/Mg alloy degradation rate by considering both their electrochemical corrosion behaviour and biological characteristics. A range of Mg alloys with varying amounts of calcium (0.8–28%) and zinc (3–10%) were cast and then machined into Ø4mm and 15mm discs for biocompatibility (HETCAM) and parallel in vitro testing. Alloys were placed in various simulated body fluid (SBF) solutions in vitro (7–28 days) to determine effect of alloy composition on degradation rate. These potentiostatic and potentiodynamic tests were designed to simulate, to varying degrees, the in vivo environment, with the crucial factors (e.g. temperature, pH, serum proteins, CO2 level) controlled to ensure consistency across the test methods. The mechanisms of corrosion on the Mg/Mg alloy microstructure and the effect of protein adsorption all played key roles in dictating the corrosion of alloys in vitro. Specifically the inclusion of physiological levels of serum proteins decreased the corrosion rate up to 600% over more standard SBF solutions described in literature. This work provides an improved understanding of the effects of corrosion variables on Mg alloys, while making major steps towards deciding the most appropriate screening tests for new alloys for their use as a biomedical material prior to moving to in vivo animal studies

Summary Statement. The constraint behavior of total knee arthroplasty (TKA) prosthesis usually has to be physically tested. This study presents a computer simulation model using finite element analysis (FEA) and demonstrates its effectiveness in predicting the femorotibial constraint behavior of TKA implants. Introduction. TKA prostheses are semi-constrained artificial joints. A well-functioning TKA prosthesis should be designed with a good balance between stability and mobility, meaning the femorotibial constraint of the artificial joint cannot be excessive or too lax. To assess the constraint behavior of a TKA prosthesis, physical testing is usually required, and an industrial test standard has been developed for this purpose. Benefiting from technological advancement, computer simulation has become increasingly useful in many industries, including medical device research and development. FEA has been extensively used in stress analysis and structural evaluation of various orthopaedic implants. This study presented an FEA-based simulation to evaluate the femorotibial constraint behavior of TKA prosthesis, and demonstrated the effectiveness of the method by validating it through physical testing. Methods. A Cruciate Retaining (CR) TKA prosthesis design (Optetrak Logic CR, size 3, Exactech, FL, USA) was used in this study. The prosthesis system consists of a femoral component, a tibial insert, and a tibial baseplate. CAD models of the implants assembled at 0° of flexion were used for the simulation. Finite element models were generated using 10-node tetrahedral elements, with all materials considered linear elastic. Boundary conditions were set up according to the ASTM F1223 standard. The tibial baseplate was fixed distally. A constant compressive force (710 N) was applied on the femoral component. Nonlinear Surface-Surface-Contact was defined at the femorotibial articulating surfaces as well as between the tibial insert and tibial baseplate. A coefficient of friction of 0.2 determined from the physical test was input into the simulation. The femoral component was driven under a displacement-controlled scheme to slide along the anterior-posterior (AP) direction on the tibial insert. At each time step, constraint force occurring at the articulating surface was derived from the reaction force at the distal fixation of the tibial baseplate. The force-displacement curve was plotted by combining the results of all time steps to characterize the constraint behavior of the prosthesis. A nonlinear FEA solver (NX Nastran SOL601, Siemens, TX, USA) was used to solve the simulation. In addition, five samples of the prostheses were physically tested per ASTM F1223. Simulation results were compared to the physical testing. Results. The simulation successfully captured the movement of contact location and pressure along the movement of the femoral component. The force-displacement curve predicted by the simulation exhibited a very close hysteresis loop profile as the results of physical testing. Using the curve slope from 0 to 5 mm to characterise the constraint in the most relevant displacement range, the simulation predicted 45.7 N/mm anteriorly and 36.4 N/mm posteriorly, which are less than 10% different from the physical testing results (46.4 N/mm anteriorly and 39.6 N/mm posteriorly). Discussion/Conclusion. This study demonstrated that the simulation was able to closely predict the femorotibial constraint behavior of the TKA prosthesis under ASTM F1223 testing. The simulation results resembled the physical test results not only in the general profile of the curve but also in the magnitude of slope values. The increased difference at the far anterior region could be related to the fact that no material nonlinearity was considered in the current simulation, a factor that could be improved in future studies. A validated simulation method could be very useful in TKA prosthesis design. Since no physical prototypes are required, design evaluation and optimization can be achieved in a much easier and faster manner

Introduction:. The prevalence of total hip (THA) and knee arthroplasty (TKA) is growing dramatically, with more than 1 million procedures performed annually in the United States. As the cost of and demand for the newest orthopaedic implants continue to rise, the price paid to medical device companies for implants is a growing concern. Some high-volume healthcare institutions have adopted price capitation strategies to control costs, in which a flat purchase price is negotiated for all implant line items regardless of technology and material. The purpose of this study was to evaluate whether the implementation of price capitation in a large health system affected trends in THA and TKA premium implant selection by surgeons. A secondary objective was to compare selection trends between surgeons with an academic center affiliation and community practice surgeons, within a single health system. Methods:. All consecutive primary THA and TKA cases six months before (1/1/2011–6/30/2011) and after (8/1/2011–1/31/2012) implementation of a capitated pricing strategy (7/1/2011) were identified. Surgeon education regarding the new pricing policy was conducted for 1-month following implementation, and data during this time were omitted from the study. After exclusions (Figure 1), a total of 481 THA and 674 TKA from the large hospital, and 253 THA and 315 TKA from the two community hospitals comprised the final study cohort. A retrospective review of patient demographics and implant characteristics for each case was performed. Premium THA implants were defined by the existence of one of the following bearing surfaces: second (2G) or third generation (3G) highly cross-linked polyethylene liner with a ceramic or oxidized-zirconium femoral head, ceramic liner with a ceramic femoral head, or mobile-bearing system. Premium TKA implants were defined by the existence of at least one of the following criterion: mobile-bearing design, high-flexion design, oxidized-zirconium femoral component, and/or highly cross-linked polyethylene bearing surface. Pearson's chi-square analyses and Fisher's exact test were used to compare implant usage between pre- and post-capitated pricing time periods. Results:. Surgeons with an academic center affiliation increased premium THA implant usage from 65.77% to 70.27% (p = 0.29), while surgeons at the community hospitals selected fewer premium implants (36.36%) and did not change their practice (p = 0.80) (Figure 2). TKA implant usage with one or more premium criteria increased from 73.37% to 89.54% (p < 0.001) for surgeons with an academic affiliation (Figure 3). Premium TKA implants (particularly mobile-bearing) were used at greater rates by our community hospital surgeons before and after price capitation, with all TKA implants having at least one premium criteria. While there was a significant increase in the use of high-flexion knee systems by community hospital surgeons (p = 0.03) following price capitation, there was an unexpected decrease in use of highly cross-linked polyethylene (p = 0.03). Conclusions:. These results highlight the effect of price capitation on implant selection by academically affiliated and community practice surgeons. There was a clear trend towards premium implant usage in TKA with price capitation, particularly for surgeons with an academic practice. No differences were detected in premium THA implant selection for either group of surgeons

The release of metallic elements from the surfaces of orthopaedic prostheses, either by leaching or breakdown of the device into the body, is a potential health problem to patients. During the endurance of this bio-material metal alloys undergo to corrosion with the possibility that metal ions interact with biofluids and tissues inducing adverse biological effects (local or systemic damage such as cytotoxicity, delayed hypersensitivity, effects on angiogenesis and mutagenicity). Indeed, as the metal ions are released over a period of time, they will continue to stimulate the inflammatory response and to influence those cells within the chronic response. The safe evaluation of biocompatibility of metallic-based orthopaedic prostheses is a prerequisite for their use in medicine. In this context, the use of in vitro model systems is of growing importance, not only as components of the initial phases of the safe evaluation process, but also as alternative (non-animal) methods for regulatory purpose through the cycle of research, development, validation and acceptance by regulatory authorities. The aim of this work is to review the activity of IMETOX (In vitro Metal Toxicology) project of ECVAM in relation to biomaterials for hard tissue substitute. The research is aiming at integrating aspects of metal toxicity in different toxicological areas (e.g. systemic toxicity, reproductive toxicity, immunotoxicity, carcinogenicity). Examples of tier testing as basis for new in vitro strategies for the evaluation of immunotoxicity, basal cyto-toxicity, and carcinogenic potential of metals of interest as components of medical devices (e.g. Ag, Co, Cr, Pt, Ti, V) investigated by cell cultures (mouse fibroblasts Balb/3T3, human keratinocytes HaCaT) are presented. Key factors influencing cellular metal toxicity (low dose exposure, speciation, interaction among elements) and the new emerging problems of the cytotoxic potential of metal-nanoparticles are discussed

Despite improvements in techniques and materials, aseptic loosening of artificial hip joints remains as the most serious problem. This study investigated mechanical and biological effects of biocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer on prevention of aseptic loosening. To examine mechanical effects of MPC grafting, we performed hip simulator tests (3million cycles) using cross-linked polyethylene (CL-PE) liners with or without nano-grafting of MPC onto articulating surface (MPC liner/CL-PE liner) and PE liner against CoCrMo heads. To examine biological responses of macrophages and osteoblasts, we prepared MPC nanoparticles (500nm). Using in vitro/vivo murine particle-induced osteolysis model, we examined biological effects of MPC nanoparticles on osteoclastogenesis. The friction torque was about 90% lower in MPC liners than control liners. Total amounts of wear produced from MPC liner was about 1/5and 1/30 of those from CL-PE and PE liners, respectively. Three-dimensional analysis and SEM analysis of MPC liners revealed no or little wear. The effect of MPC nanografting was maintained even after the test, because XPS analysis confirmed the remainder of specific spectra of MPC on the liner surface. When nanoparticles were exposed to cultured mouse macrophages, MPC nano particles were hardly phagocytosed by macrophages and did not enhance the concentration of bone resorptive cytokines and PGE2. Furthermore, culture medium of macrophages exposed to MPC nanoparticles did not induce RANKL expression in osteoblasts and osteoclastogenesis from bone marrow cells. In vivo murine osteolysis model, particle-induced bone resorption was hardly observed in mice implanted MPC nanoparticles. Some medical devices grafted MPC onto itssurface have been already used under authorization of the FDA. This study demonstrated that MPC grafting markedly decreases wear production. In addition, even if wear particles are produced, they are biologically inert in respect to phagocytosis by macrophages and subsequent resorptive actions, suggesting an epochal improvement of artificial hip joints preventing aseptic loosening

Introduction: It is noted that infections make up the most feared complications of prostheses’ surgery in orthopaedic implants after resection of primary or secondary cancer of limb bones. The causes must be attributed to the entity of the skeletal resection and of surrounding soft tissues sacrifice, to the duration of surgery and to the pre-operative cycle of chemotherapy or radiotherapy. Infections of prostheses in oncology are caused mainly by bacteria present either in isolated strains or in poly-microbic associations, and most recently fungus infections have begun to be found, in immunodepressed patients. Candidemia makes up an important cause of systemic infections in immuno-compromised oncological patients, who received high doses of chemotherapy; moreover candidemia represents a high risk of hospital sepsis. It is noted that the behaviour of the Candida is interpreted through the production of a biofilm and then the inhibition of the production of the biofilm itself is translated into a potential antifungal effect. From the analysis of the literature a protective role carried out by the silver coating of the tumoural prostheses towards the bacterial infections is deduced. It is noted, in fact, the antimicrobiotic effect of medical devices coated in silver; in particular in studies conducted in animals favourable results were demonstrated on bacterial adherence of titanium devices coated with silver. The aim of the study was to evaluate in vitro the inhibition of the production of biofilm by different strains of Candida in the presence of titanium and titanium coated with silver. Materials and Methods: Six strains of Candida were analyzed: 2 strains of C. albicans, 2 of C. tropicalis and 2 of C. parapsilosis. The fungal strains were stratified on discs of pure titanium, a material in which implants of tumoural prostheses are made, and furthermore on discs of titanium coated in silver, and the ability of the fungus to produce protective biofilm on different substratum was evaluated. All of the studies were conducted 3 times. The adherence to the biofilm was measured by semi-quantitative, colormetric and spettrophotometric methods according to standardized protocols. Results: The spettrophotometric analysis demonstrated a statistically significant reduction of the production of biofilm by fungus strains that came in contact with titanium coated in silver compared to pure titanium in all of the strains that were examined, attested by the fact that the silver creates a micro-environment unfavourable for fungus growth. Conclusion: The analysis of the results demonstrated that the Silver coating of the oncological prosthesis made an unfavourable micro-environment not only for bacteria, as has already been widely established, but also for fungus. For this reason we maintain that this coating constitutes a valid opportunity in oncological resections for those patients who, being treated with chemotherapy, radiotherapy and to long hospitalitations present an elevated risk of fungal infection in oncological resections. From the studies we conducted it appeared how fundamental the use of silver in tumoural prosthesis is in order to prevent contamination by fungal strains and how this use must be taken more and more into consideration to improve life expectancy of a particular and sensitive category of patients, especially oncological

Aims

The use of 3D-printed titanium implant (DT) can effectively guide bone regeneration. DT triggers a continuous host immune reaction, including macrophage type 1 polarization, that resists osseointegration. Interleukin 4 (IL4) is a specific cytokine modulating osteogenic capability that switches macrophage polarization type 1 to type 2, and this switch favours bone regeneration.

Purpose: Disposable medical devices have several advantages and are widely used. But since the financial burden of disposable devices is however significant for the hospital budget, it would be interesting to reassess multiple use devices in terms of efficacy and safety. The purpose of this study was to determine the safety aspects involved and to assess wear observed in new versions of autoclavable shavers and drill bits used in arthroscopic surgery. Material and methods: After standard preparation and ten sterilisation cycles, fifteen instruments (shavers and drill bits) were used 10 times each during arthroscopic procedures performed on non-embalmed cadavers. The instruments were used on tissues, cartilage or tendons (shavers) or cancellous bone (drill bits). Duration of use was at least 10 min for each instrument. The instruments underwent standard preparation (decontamination-cleaning-immersion in 1N caustic solution) followed by sterilisation at 134°C for 20 minutes as defined by the regulatory decree (n° 138, 14 March 2001). A tracability sheet was completed at each order for sterilisation. The first phase consisted in an evaluation of the instrument’s resistance to sterilisation treatments, in particular the non-alteration of the cutting surface examined under optical magnification. The second phase was to determine the feasibility and performance level of the cleaning step based on assay of protein residue with UV spectrophotometry as described by Bradford. Results: One hundred fifty complete cycles were performed. The results of the first phase demonstrated satisfactory instrument resistance to 10 uses with traces of erosion visible on 20% of the instruments after the 5th use. Two instruments were replaced during the study due to mechanical wear. The second phase revealed positive results in 2% of the cases (residual proteins > 8 μg/ml), the positivity threshold defined by the Pr EN ISO 15883-1 normalisation project concerning general requirements for desinfecting cleaners. Analysis of these results demonstrated that 12% of the instruments cleaned with ultrasounds carried traces of protein residues. There was no trace of proteins on instruments cleaned with a washing machine operating on the “endoscope” cycle, i.e. 143 successive cycles. Discussion: Despite the difficulty in cleaning (double sheath), shavers and drill bits used in arthroscopic surgery can be reused without risk since the traces of residual protein are negligible when the instruments are cleaned with a endoscope-quality desinfecting washing machine. In addition, despite intensive use, wear is acceptable for ten cycles. Extensive use of disposable instruments should be carefully debated due to the financial consequences

Aims

To find out if there is an inverse association between estimated glomerular filtration rate (eGFR) and whole blood cobalt (Co) and chromium (Cr) levels in patients with metal-on-metal (MoM) hip arthroplasties and renal insufficiency, suggesting that renal insufficiency could cause accumulation of Co and Cr in blood.

Aims

This is a multicentre, non-inventor, prospective observational study of 503 INFINITY fixed bearing total ankle arthroplasties (TAAs). We report our early experience, complications, and radiological and functional outcomes.

Aims

The STRYDE nail is an evolution of the PRECICE Intramedullary Limb Lengthening System, with unique features regarding its composition. It is designed for load bearing throughout treatment in order to improve patient experience and outcomes and allow for simultaneous bilateral lower limb lengthening. The literature published to date is limited regarding outcomes and potential problems. We report on our early experience and raise awareness for the potential of adverse effects from this device.

Aims

To establish our early clinical results of a new total knee arthroplasty (TKA) tibial component introduced in 2013 and compare it to other designs in use at our hospital during the same period.

Aims

To draw a comparison of the pullout strengths of buttress thread, barb thread, and reverse buttress thread bone screws.

Aims

The optimum clearance between the bearing surfaces of hip arthroplasties is unknown. Theoretically, to minimize wear, it is understood that clearances must be low enough to maintain optimal contact pressure and fluid film lubrication, while being large enough to allow lubricant recovery and reduce contact patch size. This study aimed to identify the relationship between diametrical clearance and volumetric wear, through the analysis of retrieved components.

Objectives

Bioresorbable orthopaedic devices with calcium phosphate (CaP) fillers are commercially available on the assumption that increased calcium (Ca) locally drives new bone formation, but the clinical benefits are unknown. Electron beam (EB) irradiation of polymer devices has been shown to enhance the release of Ca. The aims of this study were to: 1) establish the biological safety of EB surface-modified bioresorbable devices; 2) test the release kinetics of CaP from a polymer device; and 3) establish any subsequent beneficial effects on bone repair in vivo.

INTRODUCTION. Nickel-Titanium (NiTi) with a molar composition of 50:50 or nitinol alloy exhibit special mechanical properties. These properties can be put to excellent use in various biomedical applications including: intravascular stent, orthodontic wires, prosthetic heart valves, angioplastic guides, orthopaedic implants, bone substitution materials, endoscopic instruments, implant stents and filters. Microorganism adhesion properties of nitinol may be decreased by oxidizing agents and surface heat treatment. In the present study, we investigated the microorganism adhesion and cytotoxicity of the thin film of nitinol and compared these properties with that of bulk form. METHODS. In this analytical comparative study, small parts of thin film and bulk form of nitinol (15 mm×15 mm) were selected and sterilized in autoclave (15 lb for 20 min). Five microorganism, four bacteria (Ecoli, staphylococcus aureus, pseudomonase aerugenosa, bacillus cereus) and one mold form of fungi (candida albicans) were selected. The sample materials (thin film and bulk forms of nitinol) were treated by microorganism suspensions in 37°C for 24h in different culture flasks. Every suspension of five microorganisms was counted before and after examination. Adherence activity of these forms of nitinol was studied by optical and electron microscopy. The interaction between the microorganisms and the two forms of nitinol alloy were studied by variation in number of microorganisms counted after introduction of these living organisms to the surface of the alloy. RESULTS. It was observed that the five separate microorganisms put in contact with the thin film in comparison with the bulk form showed lower decrease rate of cells (mean decrease rate of 39% for thin film, 62% for bulk form, sd < 0.05). On the thin film, a decrease rate of 14% for Ecoli, 44% for P. aeroginesia, 30.1%for S. aureus, 22% for B. cereus and 6.4% for C. albicans were registered. However, for cells in contact with the bulk form nitinol, decrease rate of cells were 39% for E. coli, 62% for P. aeroginosa, 61.9% for S. aureeus, 49% for B. cereus and 31% for C. albicans. DISCUSSION & CONCLUSIONS. In this study, in every forms of nitinol alloy (thin film and bulk), microorganisms numbers were declined. Thin film nitinol exhibits lower decrease rate of cells at the end of the test. This shows that this thin film nitinol have less cytotoxicity for bacterial and fungal cells in comparison with the bulk. As it appears in electron microscopic micrographs, higher adherence activity of the thin film can be attributed to smoothness and lower amount of nickle released form this surface. This property detected in vitro study may be also appeared in vivo. These different behaviours of the two forms of nitinol alloy is probably due to the better biocompatibility of the thin film. This new form of alloy with its better qualities can be a promising process for developing medical prosthetic devices

Implant-related infection is one of the leading reasons for failure in orthopaedics and trauma, and results in high social and economic costs. Various antibacterial coating technologies have proven to be safe and effective both in preclinical and clinical studies, with post-surgical implant-related infections reduced by 90% in some cases, depending on the type of coating and experimental setup used. Economic assessment may enable the cost-to-benefit profile of any given antibacterial coating to be defined, based on the expected infection rate with and without the coating, the cost of the infection management, and the cost of the coating. After reviewing the latest evidence on the available antibacterial coatings, we quantified the impact caused by delaying their large-scale application. Considering only joint arthroplasties, our calculations indicated that for an antibacterial coating, with a final user’s cost price of €600 and able to reduce post-surgical infection by 80%, each year of delay to its large-scale application would cause an estimated 35 200 new cases of post-surgical infection in Europe, equating to additional hospital costs of approximately €440 million per year. An adequate reimbursement policy for antibacterial coatings may benefit patients, healthcare systems, and related research, as could faster and more affordable regulatory pathways for the technologies still in the pipeline. This could significantly reduce the social and economic burden of implant-related infections in orthopaedics and trauma.

Cite this article: C. L. Romanò, H. Tsuchiya, I. Morelli, A. G. Battaglia, L. Drago. Antibacterial coating of implants: are we missing something? Bone Joint Res 2019;8:199–206. DOI: 10.1302/2046-3758.85.BJR-2018-0316.

Aims

The aim of this study was to conduct the largest low contact stress (LCS) retrieval study to elucidate the failure mechanisms of the Porocoat and Duofix femoral component. The latter design was voluntarily recalled by the manufacturer.

Objectives

The aim of this study was to review the current evidence and future application for the role of diagnostic and therapeutic ultrasound in fracture management.

Aims

Between 15% and 20% of patients remain dissatisfied following total knee arthroplasty (TKA). The SAIPH knee system (MatOrtho, Surrey, United Kingdom) is a medial ball and socket TKA that has been designed to replicate native knee kinematics in order to maximize the range of movement, stability, and function. This system is being progressively introduced in a stepwise fashion, with this study reporting the mid-term clinical and radiological outcomes.

Aims

The purpose of this study was to compare two different types of metal-on-metal (MoM) bearing for total hip arthroplasty (THA): one with a large femoral head (38 mm to 52 mm) and the other with a conventional femoral head (28 mm or 32 mm). We compared clinical outcome, blood metal ion levels, and the incidence of pseudotumour in the two groups.